VulnerabilityModified
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.
HIGH 8.8EPSS 1.26%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 1.26% probability · 68th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Affected
- mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1698503Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-14/Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-15/Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-16/Release Notes, Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1698503Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-14/Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-15/Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-16/Release Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.