title: Junos OS: An unauthenticated attacker with local access to the device can create a backdoor with root privileges
description:
An Incorrect Default Permissions vulnerability in Juniper Networks Junos OS allows an unauthenticated attacker with local access to the device to create a backdoor with root privileges. The issue is caused by improper directory permissions on a certain system directory, allowing an attacker with access to this directory to create a backdoor with root privileges.
This issue affects Juniper Networks Junos OS:
*  All versions prior to 20.4R3-S5;
*  21.1 versions prior to 21.1R3-S4;
*  21.2 versions prior to 21.2R3-S4;
*  21.3 versions prior to 21.3R3-S3;
*  21.4 versions prior to 21.4R3-S1.
problem types: CWE-276 Incorrect Default Permissions
affected:
{
defaultStatus: unaffected
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S5, status: affected, version: 0, versionType: semver
lessThan: 21.1R3-S4, status: affected, version: 21.1, versionType: semver
lessThan: 21.2R3-S4, status: affected, version: 21.2, versionType: semver
lessThan: 21.3R3-S3, status: affected, version: 21.3, versionType: semver
lessThan: 21.4R3-S1, status: affected, version: 21.4, versionType: semver
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 8.4
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
version: 3.1
]
format: CVSS
scenarios: GENERAL
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue: Junos OS 20.4R3-S5, 21.1R3-S4, 21.2R3-S4, 21.3R3-S3, 21.4R3-S1, 22.1R1, and all subsequent releases.
workarounds: There are no known workarounds for this issue.