CVE-2021-29951

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

Description

The Mozilla Maintenance Service granted SERVICE_START access to BUILTIN|Users which, in a domain network, grants normal remote users access to start or stop the service. This could be used to prevent the browser update service from operating (if an attacker spammed the 'Stop' command); but also exposed attack surface in the maintenance service. *Note: This issue only affected Windows operating systems older than Win 10 build 1709. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 78.10.1, Firefox < 87, and Firefox ESR < 78.10.1.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-29951

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-29951.html

OS impact

OSVersionStatusFixed in
arch archaffected
suse slesaffected
debian debianbookwormfixed0
debian debianbullseyefixed0
debian debianforkyfixed0
debian debiansidfixed0
debian debiantrixiefixed0

References

Verify integrity in audit chain (admin only). AS-IS.