Vulnerability · Published Oct 25, 2021 · Assigned by GitHub_M

CVE-2021-39221XSS in Contacts

Medium 6.4

In plain English

A medium-severity unrestricted file upload in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).

Severity (CVSS 3.1)6.4Medium

Exploit odds (30 days)0.5%top 55.6% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Contacts application prior to version 4.0.3 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 Contacts application is upgraded to 4.0.3. As a workaround, one may use a browser that has support for Content-Security-Policy.

Affected products (as reported)

Vendor	Product	Versions
nextcloud	security-advisories	< 4.0.3

Weakness: CWE-434, CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-j6cx-mxqf-f9vc x_refsource_CONFIRM
https://github.com/nextcloud/contacts/pull/2407 x_refsource_MISC