Privilege escalation in Mozilla Firefox
CVE-2021-23999
If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to web content. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
Vulnerability class: Privilege Escalation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.014 (71.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 71.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.013 · newest: 0.014 · change: +0.001
Affected products
- 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/mfsa2021-14/ (Release Notes, Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-16/ (Release Notes, Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-15/ (Release Notes, Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Exploit, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-23999?
- CVE-2021-23999 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Privilege Management. CVSS score: 8.8/10. Published 2021-06-24.
- How severe is CVE-2021-23999?
- High severity. CVSS v3 base score is 8.8 out of 10.