# Privacy and Security of Women’s Reproductive Health Apps in a Changing Legal
Landscape

Shalini Saini
Texas A&M University Nitesh Saxena
Texas A&M University

###### Abstract

FemTech, a rising trend in mobile apps, empowers women to digitally manage
their health and family planning. However, privacy and security
vulnerabilities in period-tracking and fertility-monitoring apps present
significant risks, such as unintended pregnancies and legal consequences. Our
approach involves manual observations of privacy policies and app permissions,
along with dynamic and static analysis using multiple evaluation frameworks.
Our research reveals that many of these apps gather personally identifiable
information (PII) and sensitive healthcare data. Moreover, around 85% of the
app privacy policies examined lack explicit mention of security measures,
despite the sensitivity of health data. Furthermore, our analysis identifies
that 61% of the code vulnerabilities found in the apps are classified under
the top-ten Open Web Application Security Project (OWASP) vulnerabilities.

Our research emphasizes the significance of tackling the privacy and security
vulnerabilities present in period-tracking and fertility-monitoring mobile
apps. By highlighting these crucial risks, we aim to initiate a vital
discussion and advocate for increased accountability and transparency of
digital tools for women’s health. We encourage the industry to prioritize user
privacy and security, ultimately promoting a safer and more secure environment
for women’s health management.

##  1 Introduction

Digital reproductive health management meets modern medicine needs for better
accessibility and continuous monitoring. Female Technology (Femtech),
particularly period-tracking and fertility monitoring apps, addresses women’s
unique health needs [18]. The Femtech market has surged tenfold in the past
decade and is projected to reach a value of $50 billion by 2025 [50]. However,
in the absence of enforced regulations, these apps are susceptible to privacy
and security attacks.

Smartphones have revolutionized healthcare by facilitating remote recording,
sharing, and access to medical assistance, particularly during the pandemic.
In North America, 88% of the population (329 million mobile users) and 75% of
networked devices/connections will be connected via Wi-Fi [4]. Mobile
technologies can enhance sexual and reproductive health by offering education,
supporting vulnerable populations, and optimizing reproductive health through
features like fertility tracking apps, contraceptive counseling, and birth
control reminders [23, 54, 33]. However, increased network connectivity poses
a risk of malicious attackers accessing users’ private information.
Reproductive health apps, leveraging users’ needs and interests, may encourage
the sharing of private data over the network, which can be exploited for
surveillance capitalism [53, 32].

Figure 1: Privacy and Security Threats of Vulnerabilities of Reproductive
Mobile Apps to Women’s Health

Mobile apps face challenges in validating integrity, reliability,
effectiveness, privacy, security, and accountability, unlike regulated medical
devices. The FDA approved Natural Cycles in 2018 as the first mobile medical
application for contraception [31]. However, it has a typical use failure rate
of up to 8.3% [21]. If an app fails to prevent pregnancy, it can result in
lawsuits and financial claims [40]. Lack of regulation and compliance
verification allows app developers to exploit user data for maximum
monetization, disregarding privacy and security. Certain permissions, default
settings, bundled permissions, and data sharing can lead to such exploitation
[43]. Figure 1 illustrates the potential threats and negative impacts of
exploiting vulnerabilities in reproductive health apps, emphasizing the harm
caused by malicious manipulation of these tools. Our study makes several
contributions including:

  * •

Our work verifies that majority of studied reproductive health apps collect
Personal Identification Information (PII), geographical data, and sensitive
health data.

  * •

The study results reveal that dangerous permissions and vulnerabilities can
grant access to restricted app activities and data, which could potentially
facilitate privacy and security attacks.

  * •

The study highlights that in the post Roe v. Wade era, period-tracking and
fertility-monitoring apps exhibit vulnerabilities that significantly increase
the risk to women’s privacy and security

  * •

The study findings call for collaboration among health professionals,
developers, and policy-makers to develop secure and trustworthy digital health
management apps for women’s health.

With Roe v. Wade overturned, period-tracking and pregnancy managing mobile
apps may be vulnerable to exploitation for tracking and identifying vulnerable
populations for legal prosecution [35, 52]. The vulnerability of users’
sensitive health data in reproductive healthcare apps is a significant concern
due to law enforcement’s ability to access data from third-party servers or
the user’s device through subpoenas. Regulatory standards are necessary to
ensure the protection of users of reproductive healthcare mobile apps, despite
the guidelines issued by the U.S. Department of Health and Human Services
(HHS). The Federal Trade Commission (FTC) safeguards sensitive health data,
even in cases not regulated by The Health Insurance Portability and
Accountability Act (HIPAA) [6, 24]. The recent case of a period-tracking app
being barred by the Federal Trade Commission (FTC) for selling personal data
to advertisers is just one example of the exploitation of unregulated
reproductive healthcare apps [42].

In areas where abortions are illegal, manipulated apps not only increase the
risk of unintended pregnancies, leading to health and social crises, but also
expose individuals to potential legal repercussions. The study highlights
significant privacy and security vulnerabilities in even the most popular
period-tracking and fertility-monitoring apps, despite their well-established
market presence. These risks are particularly worrisome for women facing
disadvantages, including limited access to essential healthcare and preventive
interventions [23]. Therefore, it is crucial to regulate secure FemTech apps
to protect the women’s reproductive health rights.

##  2 Background

The 2020 CDC Abortion Surveillance Report shows that 615,911 abortions were
reported, with an abortion rate of 11.2 per 1,000 women aged 15-44 years [3].
Unintended teen pregnancies pose a social, medical, and financial burden. Teen
pregnancy rate dropped 64% between 1991 and 2015, resulting in $4.4 billion in
public savings in 2015 alone [1, 2]. However, 30% of women aged 13-44 in the
United States are in need of publicly funded contraception, and 98% lack
reasonable access to these resources, particularly vulnerable populations such
as young women in foster care [2, 1].

###  2.1 Health Risks of Legal Disparity

The right to abortion is an essential liberty tied to basic rights such as
family matters and bodily autonomy [7]. Unsafe abortion practices pose grave
risks, including potential fatalities. However, accessing safe and legal
abortion services can be difficult, especially for vulnerable populations. The
COVID-19 pandemic has compelled healthcare providers to adopt telemedicine,
but this shift raises concerns regarding privacy and security. Furthermore,
the overturning of Roe v. Wade has sparked fears that individuals’ menstrual
cycle data obtained through apps could be exploited for legal prosecution
purposes [35, 52]. Period-tracking mobile apps may falsely claim to protect
privacy and data security, and unauthorized access to healthcare-related data
can be exploited. More evidence-based studies are needed to build trust in
their clinical utility, efficacy, and safety. There are known biases and
trends that can result in targeted attacks for the purpose of monetizing these
predictions, and to gain behavioral control [53].

###  2.2 Privacy, Security, and Legal Risks of Women’s Health Apps

Reproductive health management mobile apps can assist women to be aware on
fertile cycle and making conscious decision about the pregnancy, but
collecting and misusing the app data can pose legal threats. There is a
possibility of biased legal actions towards minorities and widening the
inequality gap [35, 49].

Period-tracking apps have raised concerns about user data security and
privacy, particularly after the overturning of Roe v. Wade, which could
potentially criminalize users [22]. Leading apps like Flo and Clue have issued
statements to protect user privacy. Flo also introduced an anonymous mode [9,
5]. App developers face challenges in assuring users while complying with
legal limitations.

Digital healthcare can reduce the burden of lower status healthcare workers,
including low-income women of color for managing healthcare and family
planning [45]. However, changes in medicine practices due to the COVID-19
pandemic and restrictions on abortion clinics have led to a significant
increase in medication abortions, potentially putting app users at risk of
prosecution for non-compliance with abortion laws if their identity is linked
through vulnerabilities in the app [16].

It is interesting to know how non-technical issues may impact the privacy and
security vulnerabilities of menstruation and fertility apps. For example,
Aljedaani et al. showed that 63% of mobile health apps lack security because
of absent security guidelines and regulations for developing secure mobile
health apps [15]. Moreover, as per Earle et al., the limited involvement of
health professionals or users in the design, development, and deployment of
period-tracking and fertility apps may restrict developers’ ability to fully
grasp the sensitivity of reproductive health data [29].

##  3 Related Work

Considering the sensitive nature of reproductive data, Shipp and Blasco
conducted an analysis of 30 mobile apps that focus on fitness and health,
specifically those tracking period data. Their primary focus was on analyzing
the privacy policies of these apps, mostly manually, and highlighting the lack
of specific information regarding the collection of period data [47]. In
comparison, our work includes a comprehensive coverage of privacy policies,
code vulnerabilities, dangerous permissions, and runtime vulnerabilities in
women’s health apps, with a total of approximately 144 million downloads. It
is crucial to emphasize that no single tool can detect all vulnerabilities
effectively.

While there are efforts to discuss the practical benefits of digital health
management for reproductive health, Lupton highlights significant ethical and
privacy implications of self-tracking through reproductive activity tracking
apps and the data they produce [38]. Another work by Epstein et al. collected
and analyzed data from multiple sources to understand menstrual cycle tracking
practices by reviewing 2,000 app reviews, surveying 687 participants, and
conducting follow-up interviews with 12 individuals. Findings reveal that
women track their cycles for various reasons, including period prediction and
healthcare discussions. Six tracking methods were identified, including
technology use and physiological awareness. However, accuracy issues were
found with apps and calendars. Gender and sexual minorities felt excluded, and
life stages like young adulthood and menopause were overlooked [30].

There is a challenge to ensure that healthcare apps, which curate sensitive
health data, undergo rigorous evaluation and meet accuracy standards [25]. A
2020 study by LaMalva and Schmeelk shows that MobSF analysis identified at
least one OWASP-defined security violation in 43.6% of studied healthcare
android apps [37]. Alfawzan et al. found that all women’s health apps,
including reproductive health apps, allowed behavioral tracking and had poor
privacy practices [14].

Iyawa et al. found that mobile apps for self-management during pregnancy show
positive impacts. however, mobile apps can be further studied for the
identification of sexually transmitted infections, early warning signs of
complexities during pregnancy and miscarriage [36]. A 2019 study by Grundy et
al. showed that 79% of Google Play medicine related health apps regularly
shared user data, and short of maintaining transparency with the app users.
Studied apps demonstrate privacy leaks inferred with sharing sensitive
information to remote server. User’s privacy is threatened by apps receiving
sensitive user data, including IP addresses and GeoIP [34]. Bull et al.
analyzed data from the Natural Cycles app and found that tracking
physiological parameters such as basal body temperature, rather than just
cycle length, is critical to clinically identifying the fertile period [21]. A
study found that the only FDA-approved Natural Cycles app, a highly effective
hormone-free contraceptive method compared to traditional methods, has a
failure rate of 8.3% and can produce unintended outcomes [46]. The review of
European apps highlights with evidence suggesting that some apps are useful
for women who do not want to rely on other methods of contraception. However,
not all apps accurately predict the fertile window, leading to potential risks
for women relying on them for pregnancy prevention. The fluid usage of
fertility apps over time increases the likelihood of unintended pregnancies
[28].

Reardon et al. conducted an investigation into information leakage in hundreds
of thousands of Android apps, primarily using dynamic analysis [39]. In
contrast to their research on general apps, our study focuses on domain-
specific Femtech apps and examines risks within their unique contexts. We use
multiple tools to cross-verify findings from static and dynamic analysis
methods, in addition to analyzing privacy policies. Our comprehensive approach
helps us identify more vulnerabilities collectively, which is particularly
significant given the evolving legal complexities surrounding abortion.

##  4 Research Objectives

Our research study is focused on a meticulous examination of the most widely
accessible and highly popular Android apps designed for tracking menstrual
cycles and ovulation in order to provide a thorough understanding of privacy
and security vulnerabilities. Our analysis of these apps’ privacy policies,
dangerous permissions, exploitable attack surface, and code flaws revealed
that vulnerable apps pose a substantial risk to users’ privacy and security.
Considering the Post Roe v. Wade abortion rule in the United States, these
risks may have legal implications. Our overarching aim is to comprehensively
identify and evaluate the privacy and security vulnerabilities inherent in
reproductive health tracking apps. This includes meticulous scrutiny of app
permissions, as we acknowledge that while certain permissions are essential
for app functionalities, they can still be exploited, posing potential risks
to privacy and security. Our research objectives are as following:

  * •

Analyze the availability of privacy policies and the information transparency.

  * •

Analyzing the vulnerabilities associated with identifiable information
collection and sharing.

  * •

Identifying the exploitable App permissions, dangerous to manipulate app
behavior and mishandle sensitive health data.

  * •

Identifying the app threat surface which can cause the unintended app behavior
and undesirable outcomes.

Table 1: Fertility, Ovulation, and Period-Tracking Mobile Apps-Downloads (M- Million; K-Thousand ; +- More than), Ratings (out of 5) and # of Reviewers App Name |  Downloads | iOS | Android
---|---|---|---
Rating |  Reviews | Rating |  Reviews
Always You: Period Tracker |  100K+ | 4 |  153 | 3.4 |  341
Birth Control - Natural Cycles |  1M+ | 4.8 |  14,771 | 4.7 |  19.8K
Clover - Safe Period Tracker |  1M+ | 4.7 |  6,597 | 4.5 |  157K
Clue Period & Cycle Tracker |  10M+ | 4.8 |  340,427 | 4.3 |  1.17M
Eve Period Tracker |  1M+ | 4.7 |  107,014 | 4.4 |  26.5K
Fertility Friend- FF App |  1M+ | 4.8 |  6,958 | 4.8 |  18K
Flo |  100M+ | 4.8 |  1,051,482 | 4.6 |  3M
Glow |  1M+ | 4.7 |  65,426 | 4.3 |  70.6K
Kindara: Fertility Tracker |  100K+ | 4.7 |  8,837 | 3.2 |  2.02K
Luna |  5K+ | 4.3 |  9 | 3.7 |  61
MagicGirl/Teen Period Tracker |  500K+ | 4.6 |  1,083 | 4.6 |  7.36K
Maya |  5M+ | 4.8 |  2,437 | 4.7 |  241K
My Calendar |  10M+ | 4.8 |  33,234 | 4.8 |  420K
MyDays X |  1M+ | 3.6 |  515 | 4.1 |  46.3K
Ovia Fertility & Cycle Tracker |  1M+ | 4.8 |  66,500 | 4.6 |  75K
Period Diary |  500K+ | 4.7 |  66,984 | 2.8 |  9.29K
Period Tracker |  10M+ | 4.8 |  61,374 | 4.6 |  360K
Premom Ovulation Tracker |  1M+ | 4.7 |  18,869 | 4.1 |  10.4K
Spot On Period Tracker |  500K+ | 4.3 |  15,211 | 4.2 |  7.33K
Stardust Period Tracker |  50K+ | 4.2 |  12,645 | 4.4 |  2.31K

##  5 Methodology

We analyzed 20 period-tracking and fertility-monitoring mobile apps available
for iOS and Android devices. We compiled a list of these apps by verifying web
search and app store details, considering criteria such as availability in
English, free download, high ratings, and a substantial number of reviewers
(indicating credibility and user trust). These apps have been recommended as
top choices for managing women’s health digitally by various online resources
[44, 51]. Table 1 presents the details of the considered period-tracking and
fertility-monitoring apps in this work.

###  5.1 Mobile App: Components

A mobile app consists of a User Interface (UI), app components,
functionalities, and permissions. The UI is represented by an Activity with
multiple screens, while a non-UI component called Service performs background
operations. The Content Provider enables data sharing within the app or with
other apps, and the Broadcast Receiver verifies the legitimacy of intents from
authorized sources [26]. App permissions grant access to device features and
data resources required for intended functionality. Android categorizes
Dangerous permissions that can provide apps with additional access to
restricted data or actions. Attackers can exploit such permissions to access
sensitive information without the user’s consent [39, 19].

###  5.2 Vulnerability Analysis Methods

####  5.2.1 Static Analysis

Static Analysis is performed using Android Studio 3.6.1. to analyze the source
code of an application to identifying the code vulnerabilities without running
the code. We acquired the latest APK file for all studied apps through an
Android mobile app APK Extractor. Extracted .APK files are decompiled with an
online APK decompiler111APK decompiler..

####  5.2.2 Dynamic Analysis

Android dynamic testing tool Drozer 2.3.4 [27] is used for dynamic analysis
for finding the attack surface and the app permissions. Drozer is a well-
known, open-source security assessment tool for Android apps [27]. Test mobile
device has a Drozer client installed, and Drozer commands were executed on
Windows 10 machine.

####  5.2.3 MobSF Analysis

Mobile Security Framework (MobSF) 222MobSF https://mobsf.live/ is an
automated, all-in-one mobile application (Android/iOS/Windows) pen-testing,
malware analysis and security assessment framework. MobSF analyzes an
individual .apk file uploaded to a Web interface. Mobsf generates a report
containing information regarding the app’s security and privacy
vulnerabilities. The comprehensive report generated by MobSF categorizes
vulnerabilities into different categories, including network security,
permissions, code analysis, and more. This report offers valuable information
to assess the overall security status of the app, providing risk ratings
ranging from low to medium and high.

###  5.3 Vulnerability Analysis Categories

We present the privacy and security vulnerabilities in four major categories
of Privacy Policy Analysis, Permissions Analysis, Attack Surface Analysis, and
Code Analysis.

####  5.3.1 Privacy Policy Analysis

We manually analyze all app policies by extracting details related to the
information being collected, the sensitivity of the collected information,
data handling and sharing policies. Additionally, we gather information on
data retention policies and data security measures as stated in the privacy
policies.

####  5.3.2 Permission Analysis

To evaluate app permissions, we adopted a two-pronged approach. Firstly, we
manually examined app permissions by installing the apps on test mobile
devices. Additionally, we conducted dynamic analysis using the security
assessment tool Drozer. Furthermore, we utilized the MobSF security framework
to generate a comprehensive report that highlights app permissions and
potential vulnerabilities that could be exploited in privacy and security
attacks.

####  5.3.3 Attack Surface Analysis

When an Android app exports a component without defined permissions, app may
allow malicious users and apps unauthorized access to sensitive interactions
and data [26]. To identify the vulnerable attack surface, we utilized Drozer
commands to execute specific tests. Additionally, we conducted an analysis
using the MobSF tool, which generated a summary of the App Components,
presenting the potential attack surface.

##  6 Data Analysis and Results

Our analyses of reproductive health tracking apps identified exploitable
vulnerabilities that could allow attackers to manipulate the app’s behavior,
exploit identifiable device and user information, and link sensitive
reproductive health data to a user’s identity. These threats pose significant
privacy and security risks to users, including legal prosecution.

###  6.1 Manual Analysis

The manual analysis focuses on a thorough examination of privacy policies to
identify potential exploitable flaws. Following federal guidelines on privacy
protection in healthcare, it is crucial to safeguard personal identification
information (PII) [10, 11]. However, examination of the studied apps uncovered
the collection of diverse identifiable data, including demographics, mobile
device IDs, and individuals’ reproductive health data.

The app collects user information as personal and account-related.
Additionally, it collects communication/user-generated content and device
information as well. The second category, known as Health Sensitive Data,
includes information such as weight, menstrual cycle data, pregnancy details
(if applicable), body temperature, body measurements, symptoms, and similar
health-related data.

####  6.1.1 Privacy Policy: Information requested from the users

We analyze the apps privacy policies for vulnerabilities associated with
identifiable information and sensitive data collection.There are only 3 out of
20 apps offer anonymous access to the app, and majority of these apps requires
an account with collecting PII and sensitive data. It is observed that 95% of
studied apps request user Email. Other most requested identifiable data is
Name (85%), Phone Number (50%), Address (45%), Location (55%), and some form
of ID (15%). Other than these primary identifiable information, age/birth year
(80%) and language (25%) can also indicate the user demographics, while if
hacked, password (45%) can be exploited for linked attacks as users have a
tendency to use exact same or similar password for multiple accounts and
services [41, 17].

Out of the studied apps, only 70% explicitly state that they collect sensitive
healthcare data. Additionally, 60% of these apps also collect
Communication/User Generated Content, while 20% request information about
others. Notably, 40% of the apps collect pictures, and 50% request payment
information. Interestingly, 65% of the apps declare collecting Other
Information, without disclosing specific details about the data collected
under this category.

####  6.1.2 Privacy Policy: Default Data Captured

Mobile apps often collect various types of information by default, without
requiring user input. It is crucial for app privacy policies to prioritize
transparency, ensuring that app users are not left unaware of the information
being collected by the app. Table 2 presents the types of information to
collect, as stated by privacy policies of studied apps. We observe that 95% of
studied apps privacy policy declare to collect IP address. With 90% apps using
cookies, these apps are prone to HTTP cookie hijacking attacks against users
on mobile devices [48]. With 85% apps collecting Device Information, these
apps may help recovering the associated user’s identity and reproductive
health activities. Approximately 75% of apps collect Time Zone/Location data,
while 70% of apps can track the features accessed by users within the app. By
gathering information like network provider, browser details, usage frequency,
and online activity, these apps can obtain significant data regarding users’
physical and digital footprints.

Table 2: Privacy Policy: Default Data Collected  Default Data Collected | % of Apps
---|---
IP Address | 95
Uses Cookies | 90
Device Information | 85
Time Zone/ Location | 75
Accessed Features Within App | 70
Internet Browser | 65
Frequency of Use | 60
Mobile Service Provider | 35
Online Activity Data | 35
Network Information | 35

####  6.1.3 Privacy Policy: Data Handling and Data Security

User options are vital in assessing the privacy and security of Femtech apps.
However, unclear privacy policies may lead to reduced app usage and not
serving as reliable resources for women in need.

Table 3: Privacy Policy: Data Handling and Security Data Handling and Security | % of Apps
---|---
Encrypted | 55
Systematic Vulnerability Scanning | 15
Penetration Testing | 10
Legal Measures | 15
Periodic Data Protection Assessments | 15
Delete / Deactivate Account | 50
Erase Data | 75
Data Retained (Account Terminated) | 20
Data Retained (Period Not Specified) | 85
Security (Not Specified/ Guaranteed) | 85

Table 3 shows that only 10% of apps conduct security penetration testing to
identify and address vulnerabilities, compromising overall app security. 55%
of apps use data encryption for anonymization, while only 15% perform security
vulnerability scanning and periodic data protection assessments. 50% of apps
lack information on deleting or deactivating user accounts in their privacy
policies. Moreover, 85% retain user data without specifying relevant details
or time periods for deleted or deactivated accounts. 20% of apps even retain
data after the account is deleted, with varying waiting periods for account
deletion, such as 30 days for Clue and 7 days for the FF App. Furthermore, if
users opt to share their personal information, the app may receive
compensation from advertisers or sponsors in exchange for disclosing the
users’ data.

Additionally, one app’s privacy policy states that users can request the
deletion of their data; however, the app retains the option to refuse such
requests and may even charge a fee if the request is deemed excessive. These
uncommon or lesser-known terms and conditions may come as a surprise to app
users, resulting in undesired data sharing, delays in data deletion, and
potential fees to be paid.

####  6.1.4 Manual Analysis of App Permissions

During our observation of app permissions on a test mobile device, we manually
collected data for both iOS and Android versions. Among iOS apps, the most
commonly requested permission, requested by 50% of the apps, is the Camera
permission. On the other hand, for Android apps, the most requested
permission, requested by 65% of the apps, is the Storage permission. While iOS
apps request fewer runtime permissions compared to Android apps, they do not
ask for permission to access Files (20%), Photos (35%), Mail, and Messages
(65%). However, these apps continue to access these resources without user
awareness, violating transparency and potentially compromising user privacy.

###  6.2 Static Analysis

Broadly, as categorized in Android Studio, we observed errors and warnings for
four categories of Accessibility, Correctness, Performance, Usability, and
Security. We further focused on identifying major security flaws in the code.
Security warnings, ranging from one to thirty-nine, indicate exploitable
vulnerabilities that can be targeted for security and privacy attacks. For
example, about 61% of studied apps in Table 4 demonstrate that the exported
service does not require permission. This indicates that these apps do not
adhere to the recommended Android behavior of securing activities with minimal
and necessary access [19, 39]. 33% of apps lack permissions for Content
Provider, and 28.57% of apps do not require permission for Receiver.
Additionally, 52.38% of studied apps use the dangerous feature
File.setReadable() to make files world-readable, potentially compromising
security. Furthermore, around 28% of apps show the vulnerability of
dynamically loading code from unsafe locations, while 23.81% of apps carry the
vulnerability of AllowBackup/FullBackupContent problems, which can be
exploited through Android Debug Bridge (adb) backup and allow users to read
all application data once backed up [20, 19].

The utilization of private APIs by all apps can lead to crashes and data loss.
These failures may result in unintended pregnancies and forced decisions,
which carry legal and health risks [8].

Table 4: Static Analysis- Security Vulnerabilities Security Vulnerabilities | # of Apps |  %
---|---|---
Exported service does not require permission | 13 |  61.90
The Network Security configuration allows the use of user certificate in the release version | 1 |  4.76
Cipher.getInstance with ECB | 4 |  19.05
File.setReadable() used to make file world-readable | 11 |  52.38
Insecure Hostname Verifier | 4 |  19.05
Receiver Does not require permission | 6 |  28.57
addJavascriptInterface Called | 2 |  9.52
Hardware ID Uage | 2 |  9.52
Potential Multiple Cerficate Exploit | 2 |  9.52
Using setJavaScriptEnabled | 2 |  9.52
Using the result of check permission calls | 2 |  9.52
load used to dynamically load code | 6 |  28.57
Content provider does not require permisiion | 7 |  33.33
AllowBackup/FullBackupContent Problems | 5 |  23.81
Insecure TLS/SSL trust manager | 4 |  19.05

###  6.3 Dynamic Analysis

In dynamic analysis of studied reproductive health mobile apps focus on
identifying dangerous permissions, attack surface, and exploitable
vulnerabilities on Android apps at runtime.

App permissions analysis helps identify potential risks to users’ privacy and
security. Standard permissions grant access to data and actions with minimal
risk, while runtime permissions provide additional access to restricted data
and actions that can impact the system and other apps. Table 5 shows the
dangerous permissions captured by the tools for the studied period-tracking
and fertility apps.

####  6.3.1 Drozer: Dangerous Permissions

Table 5: Apps Dangerous Permissions: Drozer and MobSF Analysis; 1-Identify, 0-Do not Identify Dangerous Permission |  Drozer |  MobSF |  Exploitable Vulnerability
---|---|---|---
ACCESS_COARSE_LOCATION |  1 |  1 |  Malicious apps can determine approximately where user is.
ACCESS_FINE_LOCATION |  1 |  1 |  Malicious apps can determine user’s location.
AUTHENTICATE_ACCOUNTS |  0 |  1 |  Allows an app to use the account authenticator for creating accounts as well as obtaining and setting passwords.
CALL_PHONE |  0 |  1 |  Malicious apps may cause unexpected calls on your phone bill.
CAMERA |  1 |  1 |  Allows an app to take pictures and videos with the camera, and collecting images
GET_ACCOUNTS |  1 |  1 |  Allows access to the list of accounts in the Accounts Service.
MANAGE_ACCOUNTS |  0 |  1 |  Allows an app to perform operations like adding and removing accounts and deleting their password.
POST_NOTIFICATION |  1 |  0 |  Allows an app to post notifications
READ_CALENDAR |  1 |  1 |  Malicious apps can use this to send your calendar events to other people.
READ_CONTACTS |  1 |  0 |  Allows an app to read the user’s contacts data.
READ_EXTERNAL_STORAGE |  1 |  1 |  Allows an app to read from external storage.
READ_PHONE_STATE |  1 |  1 |  An app can determine the phone number and serial number of this phone, whether a call is active, the number that call is connected to and so on.
RECORD_AUDIO |  1 |  1 |  Allows an app to access the audio record path.
SYSTEM_ALERT_WINDOW |  0 |  1 |  Malicious apps can take over the entire screen of the phone.
USE_CREDENTIALS |  0 |  1 |  Allows an app to request authentication tokens.
WRITE_CALENDAR |  1 |  1 |  Malicious apps can use this to delete or modify calendar events or to send emails.
WRITE_EXTERNAL_STORAGE |  1 |  1 |  Allows an app to write to external storage.

A per Table 6, there are 12 different dangerous permission identified in
Drozer dynamic analysis [27]. Max 62% of apps have READ_EXTERNAL_STORAGE
permission, while 43% apps have WRITE_EXTERNAL_STORAGE. Approximately 33% of
apps have permission to track the user’s approximate location through the
COARSE_LOCATION permission, while 25% of apps can track the user’s more
accurate fine location, posing greater risks to privacy and security.
Additionally, 29% of apps have CAMERA permissions to access sensitive
audio/video content. About 14% of apps may have the capability to access and
manipulate user accounts. Furthermore, 10% of these apps can access audio
recording functionality, and 5% of apps have permissions to read and write the
calendar.

Table 6: Dangerous Permissions Carried by Studied Period-Tracking Apps: Drozer and MobSF Analysis Dangerous Permissions |  | Drozer
---
(% of Apps)
| MobSF
---
(% of Apps)
ACCESS_COARSE_LOCATION | 33 | 30
ACCESS_FINE_LOCATION | 24 | 20
AUTHENTICATE_ACCOUNTS | 0 | 20
CALL_PHONE | 0 | 5
CAMERA | 29 | 25
GET_ACCOUNTS | 14 | 15
MANAGE_ACCOUNTS | 0 | 15
POST_NOTIFICATIONS | 29 | 0
READ_CALENDAR | 5 | 5
READ_CONTACTS | 5 | 0
READ_EXTERNAL_STORAGE | 62 | 50
READ_PHONE_STATE | 10 | 10
RECORD_AUDIO | 10 | 10
SYSTEM_ALERT_WINDOW | 0 | 5
USE_CREDENTIALS | 0 | 20
WRITE_CALENDAR | 5 | 5
WRITE_EXTERNAL_STORAGE | 43 | 60

####  6.3.2 Drozer: Attack Surface

Table 7 shows that activities are most vulnerable with as high as 39
activities exported by a single app. We observed total 239 components exported
forming the attack surface for 20 period-tracking apps. Activities exported
are forming 44.77% (107) of all exposed attack surface components identified
for studied apps. Content Provide is least vulnerable with 4.18% (10), while
unprotected Service (21% (51)) and Broadcast Receiver (29% (71)) components
may allow attackers to access sensitive information and manipulating app
behavior.

Table 7: Attack Surface: Drozer and MobSF Analysis
(AE- Activity Exported, BRE- Broadcast Receiver Exported, CPE- Content Provider Exported, SE-Service Exported) | Drozer | MobSF
---|---|---
App Name |  | AE
---
| BRE
---
| CPE
---
SE |  | AE
---
| BRE
---
| CPE
---
SE
Always You: Period Tracker | 2 | 3 | 1 |  2 | 1 | 3 | 1 |  3
Birth Control - Natural Cycles | 2 | 2 | 0 |  1 | 3 | 3 | 1 |  2
Clover - Safe Period Tracker | 1 | 2 | 0 |  1 | 0 | 1 | 0 |  2
Clue - Period & Cycle Tracker | 39 | 4 | 0 |  5 | 38 | 4 | 0 |  5
Eve - Period Tracker | 7 | 7 | 4 |  5 | 6 | 7 | 4 |  6
Fertility Friend FF App | 2 | 1 | 0 |  0 | 1 | 1 | 0 |  1
Flo | 7 | 4 | 0 |  3 | 6 | 4 | 0 |  4
Glow | 8 | 7 | 3 |  5 | 7 | 7 | 3 |  6
Kindara: Fertility Tracker | 2 | 1 | 0 |  4 | 1 | 1 | 0 |  4
Luna | 1 | 1 | 0 |  0 | 0 | 1 | 0 |  0
MagicGirl/Teen Period Tracker | 1 | 1 | 0 |  2 | 0 | 1 | 0 |  2
Maya | 5 | 5 | 0 |  2 | 4 | 5 | 0 |  2
My Calendar | 1 | 6 | 0 |  4 | 0 | 6 | 0 |  4
MyDays X | 1 | 2 | 1 |  3 | 0 | 2 | 1 |  3
Ovia Fertility & Cycle Tracker | 5 | 6 | 0 |  2 | 4 | 6 | 0 |  3
P.Tracker | 2 | 2 | 1 |  4 | 1 | 2 | 1 |  4
Period Diary | 4 | 1 | 0 |  2 | 3 | 1 | 0 |  3
Premom Ovulation Tracker | 8 | 5 | 0 |  2 | - | - | - |  -
Spot On Period Tracker | 2 | 4 | 0 |  2 | 1 | 4 | 0 |  3
Stardust Period Tracker | 7 | 7 | 0 |  2 | 10 | 4 | 1 |  2

####  6.3.3 Drozer: Injection Vulnerabilities

SQL injection attack can expose private data, corrupt database contents, and
even compromising of back-end infrastructure [13]. Among the studied apps, 19
out of 20 did not show any SQL injection vulnerabilities in content providers.
However, one app was found to be vulnerable, with instances of projection and
selection vulnerabilities. Injection vulnerabilities can lead to the exposure
of sensitive data, bypassing security measures, and potential damage to
databases. The impact includes risks to user privacy, loss of intellectual
property, and compromised trust in app providers [13].

###  6.4 MobSF Analysis

We performed the MobSF analysis to compare the app privacy and security
vulnerabilities compared with other analysis performed in this study. MobSF
provides an overall security score (1-100) to show the security risk level of
the app. 10% apps show Low Risk, 75% apps are with Medium Risk with 40-59
score, and other 15% apps show High Risk.

MobSF- Dangerous Permissions: A per Table 6, there are 15 different dangerous
permission identified MobSF analysis. Max 50% of apps have
READ_EXTERNAL_STORAGE permission, while 60% apps have WRITE_EXTERNAL_STORAGE.
Coarse location permission can track the user’s approximate location and 30%
apps have permission to do so, while 20% apps can track fine location of users
which is potentially more damaging to user’s privacy and security. 25% apps
have Camera permissions to access sensitive audio/video content. 20% of apps
show permission to authenticate account. 15% of Apps may have capability to
access and manipulate the accounts. 10% of these apps can access audio record
functionality and 5% of apps can read and write the calendar.

MobSF- Attack Surface: There are a total of 220 components exported identified
in MobSF analysis. There are are 39% (86) Activity Exported (AE), Broadcast
Receiver Exported (BRE) as 29% (63), Content Provider Exported (CPE) as
5%(12), and 27% (59) are Service Exported (SE).

MobSF- Network Security:  According to MobSF analysis, apps are considered
highly vulnerable if their Domain config allows clear text traffic to domains
within the scope.

MobSF- Code Analysis:  Code analysis by MobSF identifies the vulnerabilities
in app code.apk files with the security standards defined by OWASP and CWE
[12, 26]. There are eighteen code vulnerabilities detected, and eleven out of
eighteen issues fall into OWASP Top 10 vulnerabilities.

20% of apps show a high risk for insecure communication, inadequate integrity
checking, and improper platform usage. These vulnerabilities can lead to Man-
in-the-Middle (MITM) attacks and Padding Oracle attacks, which can result in
unauthorized access to data and decryption of protected sensitive reproductive
health information. Other concerning code vulnerabilities include the usage of
hardware IDs, disclosure of IP addresses, SQL injection, and hard-coded
sensitive information.

MobSF- Network Security and Certificate Analysis:  20% of studied apps found
as Secure on network security, and 15% of apps present high risk. Insecure
configuration refers to settings that do not enforce secure communication
protocols, such as using encryption or secure channels for transmitting
sensitive data. Clear text traffic refers to data transmitted without
encryption, making it susceptible to interception and unauthorized access.
About 60% of studied apps do not show information about network security.

Android apps are signed with digital certificates to ensure authenticity and
integrity, with multiple signatures (v1, v2, and v3) available to maintain
validity and security. A false signature could indicate that the app’s
certificate has been tampered with or modified, potentially indicating
malicious intent. MobSF analysis shows that 20% of apps have v1 signature as
false, and 35% of studied period-tracking apps show v3 signature as false. A
violation of an app’s authenticity and integrity can call into question the
validity of its behavior and guidance for managing monthly cycles or fertility
monitoring.

Threat of Hidden and Undetected Dangerous Permissions: In our manual analysis,
we identified seven different types of dangerous permissions. However, MobSF
identified fifteen dangerous permissions, compared to twelve identified by
Drozer. Table 5 provides a summary of all the dangerous permissions observed
by both tools. Interestingly, Drozer revealed a larger attack surface (239)
compared to MobSF (220), indicating a higher potential for security
vulnerabilities. Different tools may detect and handle app vulnerabilities
differently, leading to varying results in vulnerability scans. Additionally,
our research has revealed that users may lack complete information about
dangerous permissions requested by apps. For instance, users may not know
whether an app is tracking their precise (FINE) or approximate (COARSE)
location or both when granting ”Location” permission. This lack of
transparency raises privacy concerns and highlights the importance of improved
communication between app developers and users regarding the use of dangerous
permissions.

###  6.5 Domain-Specific Implications

In the context of period tracking and pregnancy monitoring apps, these privacy
and security breaches can be particularly alarming. Users may be sharing
highly sensitive and personal information about their menstrual cycles,
fertility, and reproductive health. If this information is mishandled, it can
have serious consequences, such as social stigma, discrimination, or even the
possibility of being used against the user in legal or personal matters.

If permissions are absent, bypassed or abused, it can result in various
privacy and security breaches. It raises concerns about potential tracking or
surveillance, particularly troubling in the context of pregnancy or abortion,
where individuals may seek to keep their reproductive choices private and
confidential. Storing and sharing of unique device identifiers could lead to
the tracking and profiling of women trying to conceive or avoiding pregnancy.
Location data can reveal sensitive information about a user’s daily routines,
potentially compromising their safety and even restricting them to get needed
medical assistance.

These apps may store sensitive information, such as medical records,
ultrasound images, or personal notes related to the period or pregnancy.
Pregnant women may share sensitive information within these apps, including
health conditions, prenatal care details, or even personal thoughts and
emotions. A breach to storage data can result in various risks, such as
identity theft, blackmail, or other forms of exploitation. Moreover, access to
contacts can be misused for unsolicited marketing or even social engineering
attacks. Invasive permissions like camera and microphone access can invade
privacy, capturing personal and intimate moments without their knowledge or
consent.

As observed in our study, the presence of an injection vulnerability in a
Femtech app pose severe consequences, such as unauthorized code execution,
data tampering, and privacy breaches. Moreover, injection vulnerabilities can
also enable attackers to modify or manipulate the app’s functionalities,
leading to unexpected or incorrect behavior. In the context of women’s health,
this could result in inaccurate ovulating period, due date calculations,
incorrect medication reminders, or other critical errors that may impact the
user’s health and well-being. This may lead to unintended pregnancies and
potentially forcing individuals into life-threatening health situations if
safe abortion options are unavailable.

Exploiting calendar access or manipulating notifications in pregnancy tracking
apps can lead to misinterpretation of ovulation cycles, increasing the risk of
unintended pregnancies. This is particularly concerning considering the
existing burden of teen pregnancies as a social and health issue.
Additionally, fine-location tracking features in these apps can pose a threat
of physical attacks, especially for individuals seeking abortions for
personal, social, financial, or health reasons. This can result in heightened
fear among women who may be concerned about being tracked and facing
unwarranted legal repercussions.

##  7 Challenges and Limitations

The app selection process was limited to find a large number of apps which are
supported by iOS and Android both. To keep the study more practical, we
analyzed free apps with better accessibility to intended population, which
also limited some of the analysis for certain apps included in the study. For
example, MobSF could not analyze the apps with very large .apk files. We
collected some data and then reshuffled the apps list to keep it consistent
with the manual, dynamic, and static analysis by utilized tools. On
vulnerabilities, we observed that there are many privacy and security warnings
observed in the code analysis, but it is out of scope to explain every
vulnerability which can be exploited to manipulate the app and user behavior
resulting in unintended outcomes. This study is limited in parts to examine
both iOS and Android app counterparts. For example, Android apps are more in-
depth analyzed with the availability of .apk files.

Period tracking and fertility monitoring apps indeed undergo frequent updates
and additions of new features. This dynamic nature poses a challenge in
identifying vulnerabilities as security assessments need to keep up with the
constantly evolving app versions. Additionally, app statistics, such as user
base, ratings, and number of reviewers, are also subject to change over time,
making it important to consider the most up-to-date information when
evaluating the app’s reputation and user feedback. Scope of this work is
limited to analyze unpaid versions. Additionally, it is important to
acknowledge that vulnerability testing tools may not provide an exhaustive
assessment. They can help identify common vulnerabilities but may not uncover
all possible security weaknesses. While our focus in this study does not
encompass the actual implementation of attacks, it serves as a foundational
exploration of the threats that could potentially exploit FemTech apps.

##  8 Further Discussion

Period-tracking apps are fast growing to assist with reproductive healthcare
needs of women, changing healthcare practices, and social environment. Legal
disparity exacerbates the contextual threat posed by vulnerabilities in
reproductive health mobile apps. These privacy and security threats have a
far-reaching impact on women’s reproductive health, affecting them physically,
mentally, and emotionally. However, the consequences are even more severe due
to the criminalization of abortion, as women bear a significantly greater
burden compared to their male counterparts. This disparity in accountability
further compounds the challenges faced by women, intensifying the overall
impact on their reproductive health.

Amid the rapid development of pregnancy monitoring mobile apps to meet market
needs, it is crucial to prioritize addressing general vulnerabilities, such as
security and data protection, while also ensuring usability and accessibility
considerations are given due attention. Neglecting these aspects can lead to
compromised user experiences, potential misuse of the app’s functionalities,
and exclusion of users with diverse needs, ultimately hindering the app’s
effectiveness and broad adoption. Developers have a responsibility to minimize
the use of dangerous permissions in pregnancy monitoring mobile apps.
Unnecessary access to sensitive features or data should be avoided, reducing
potential privacy and security risks. Additionally, when users deny certain
permissions, developers should handle these denials appropriately, gracefully
degrading the app’s functionality without compromising usability. Enforced
guidelines and rules can make developers more accountable while following best
practices proposed by development frameworks and the federal government can
minimize attack surfaces. Authentic guidance for selecting reproductive health
management apps, backed by clinical trials and vetted by authorities such as
FDA, FTC, NIH, and HHS, can help users make secure and safe choices.

Post Roe v. Wade, there is an increased attention by app developers to provide
anonymous access but implementation may take longer with technical and
operational challenges [9, 5]. We should not be waiting for major incidents to
happen before being forced to react. Developing a framework for evaluating
period-tracking apps pre-market may minimize the post-market privacy and
security breaches. It can also reduce the burden on legal system and the cost
of unintended pregnancies, which is still a known healthcare burden in the
United States [49, 2, 3]. A longitudinal study can observe patterns in
developing sensitive health data handling apps with improved security by
design, informing future policies to protect user privacy and security for
women’s health apps.

##  9 Conclusion

In this work, we analyze the privacy and security vulnerabilities of period-
tracking mobile apps impacting women reproductive health management.
Availability of these apps are promising to provide a way to reach out to
disadvantaged population, which is at greater risk without proper needed
medical consultation and assistance. However, these apps can be exploited in
multiple ways because of existing technical loopholes. App development faces
challenges in complying with secure practices due to rapidly changing market
needs. Period-tracking and fertility apps lack HIPAA regulation but are
subject to FTC rules for protecting sensitive health data. Transparent privacy
policies help users make informed decisions and trust these apps. However,
relying solely on peer evaluations may overlook privacy and security pitfalls
in the apps’ policies.

Manipulated period-tracking apps can result in unintended pregnancies and
risky decisions, such as abortion. Identifying and tracking users’
reproductive patterns post Roe v. Wade poses a serious threat to an already
burdened population. Inaccessible medical resources further endanger patient
health and lives during illegal abortions [49].

Our study exposed privacy and security vulnerabilities in period-tracking and
fertility-monitoring apps, posing legal risks in the post Roe v. Wade era.
These threats strain social, financial, and legal resources. Defining and
enforcing standards can ensure app developers adhere to security-by-design
principles and accountability. Collaboration among medical professionals,
users, developers, and legal experts fosters secure digital health management
tools, reducing the overall healthcare burden.

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