Privilege escalation in Microsoft Windows
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.
Vulnerability class: Privilege Escalation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.019 (78.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 78.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000
Affected products
- Microsoft Windows
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Firefox Esr
- Mozilla Thunderbird — versions unspecified
Weakness classification (CWE)
References
- www.mozilla.org/security/advisories/mfsa2021-10/ (Release Notes, Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-18/ (Release Notes, Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-19/ (Release Notes, Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-29951?
- CVE-2021-29951 is a medium-severity vulnerability in Microsoft Windows, classified under Improper Privilege Management. CVSS score: 6.5/10. Published 2021-06-24.
- How severe is CVE-2021-29951?
- Medium severity. CVSS v3 base score is 6.5 out of 10.