CVE-2021-29951: mozilla firefox Improper Privilege Management
Vulnerability summary
CVE-2021-29951 is a medium (CVSS 6.5) Improper Privilege Management vulnerability in mozilla firefox. EPSS estimates a 1.85% chance of exploitation in the next 30 days, higher than 78.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 8 · Related 8Timeline
- 24-06-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
2 scores · 1 source · 2 versionsEPSS trend
Probability
1.85%
Chance of exploitation in the next 30 days
Percentile
79%
Versus all other CVEs
30-day change
0.00 pp
From 1.85% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Mozilla3 products
- firefox≥ unspecified, < 87 | < 87.0
- firefox_esr≥ unspecified, < 78.10.1 | < 78.10.1
- thunderbird≥ unspecified, < 78.10.1 | < 78.10.1
1 vendor · 3 products