Vulnerability in Mozilla Firefox
CVE-2021-23995
When Responsive Design Mode was enabled, it used references to objects that were previously freed. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
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: 0.012 (67.2th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
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 (Permissions Required, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-23995?
- CVE-2021-23995 is a high-severity vulnerability in Mozilla Firefox, classified under Operation on a Resource after Expiration or Release. CVSS score: 8.8/10. Published 2021-06-24.
- How severe is CVE-2021-23995?
- High severity. CVSS v3 base score is 8.8 out of 10.