CVE-2021-39222 Information

Description

Nextcloud is an open-source self-hosted productivity platform. The Nextcloud Talk application was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation a user would need to right-click on a malicious file and open the file in a new tab. 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 Talk application is upgraded to patched versions 10.0.7 10.1.4 11.1.2 11.2.0 or 12.0.0. As a workaround use a browser that has support for Content-Security-Policy.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Reference

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xhxq-f4vg-jw5g https://hackerone.com/reports/1135481 https://github.com/nextcloud/spreed/pull/542

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

CHANGED

Integrity Impact

LOW

Availability Impact

LOW

Base Score

NONE

Base Severity

6.1