Integer overflow in Mozilla Firefox
CVE-2021-29946
Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
Vulnerability class: Integer Overflow
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: 0.013 (69.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.4% 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: 0.013 · 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 (Permissions Required, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-29946?
- CVE-2021-29946 is a high-severity vulnerability in Mozilla Firefox, classified under Integer Overflow or Wraparound. CVSS score: 8.8/10. Published 2021-06-24.
- How severe is CVE-2021-29946?
- High severity. CVSS v3 base score is 8.8 out of 10.