Medium severity · published Nov 15, 2021
CVE-2021-39222
Nextcloud is an open-source, self-hosted productivity platform
6.1
CVSS
1.1%
EPSS
No
On KEV
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
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 65% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TA
Talk · Nextcloud
before 10.0.7; 10.1.0 before 10.1.4; 11.0.0 before 11.1.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-39222
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-39222
Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xhxq-f4vg-jw5g
Third Party Advisory
https://github.com/nextcloud/spreed/pull/542
Permissions Required
https://hackerone.com/reports/1135481
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