Related Vulnerabilities: CVE-2021-29951  

A security issue has been found in Thunderbird for Windows before version 78.10.1. The 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.

Severity Medium

Remote Yes

Type Denial of service

Description

A security issue has been found in Thunderbird for Windows before version 78.10.1. The 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.

AVG-1914 thunderbird 78.10.0-1 Medium Not affected

https://www.mozilla.org/en-US/security/advisories/mfsa2021-19/#CVE-2021-29951
https://bugzilla.mozilla.org/show_bug.cgi?id=1690062