CVE-2021-29951

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.

• CWE-269

• https://bugzilla.mozilla.org/show_bug.cgi?id=1690062Issue Tracking, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-10/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-18/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-19/Release Notes, Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1690062Issue Tracking, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-10/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-18/Release Notes, Vendor Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-19/Release Notes, Vendor Advisory

Published

Jun 24, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-29945The WebAssembly JIT could miscalculate the size of a return …6.5
• CVE-2021-29946Ports that were written as an integer overflow above the bou…8.8
• CVE-2021-29947Mozilla developers and community members reported memory saf…8.8
• CVE-2021-29948Signatures are written to disk before and read during verifi…2.5
• CVE-2021-29949When loading the shared library that provides the OTR protoc…7.8
• CVE-2021-29950Thunderbird unprotects a secret OpenPGP key prior to using i…7.5
• CVE-2021-29952When Web Render components were destructed, a race condition…7.5
• CVE-2021-29953A malicious webpage could have forced a Firefox for Android …6.1
• CVE-2021-29954Proxy functionality built into Hubs Cloud’s Reticulum softwa…9.8
• CVE-2021-29955A transient execution vulnerability, named Floating Point Va…5.3
• CVE-2021-29956OpenPGP secret keys that were imported using Thunderbird ver…4.3
• CVE-2021-29957If a MIME encoded email contains an OpenPGP inline signed or…4.3