title: Cross-Site Scripting in Nextcloud Circles
description: Nextcloud Circles is an open source social network built for the nextcloud ecosystem. In affected versions the Nextcloud Circles application is vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Circles application is upgraded to 0.21.3, 0.20.10 or 0.19.14 to resolve this issue. As a workaround users may use a browser that has support for Content-Security-Policy. A notable exemption is Internet Explorer which does not support CSP properly.
problem types: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
affected:
{
product: security-advisories
vendor: nextcloud
versions:
status: affected, version: < 0.19.1
status: affected, version: >= 0.20.0, < 0.20.10
status: affected, version: >= 0.21.0, < 0.21.3
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5.8
baseSeverity: MEDIUM
confidentialityImpact: HIGH
integrityImpact: NONE
privilegesRequired: LOW
scope: CHANGED
userInteraction: REQUIRED
vectorString: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N
version: 3.1
]