CVE-2021-43534
Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
- 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
- 1.21% probability · 67th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird · debian/debian linux
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1606864%2C1712671%2C1730048%2C1735152Broken Link, Issue Tracking, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
- https://www.debian.org/security/2021/dsa-5026Third Party Advisory
- https://www.debian.org/security/2022/dsa-5034Issue Tracking, Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-49/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-50/Vendor Advisory
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1606864%2C1712671%2C1730048%2C1735152Broken Link, Issue Tracking, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/12/msg00030.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/01/msg00001.htmlMailing List, Third Party Advisory
- https://www.debian.org/security/2021/dsa-5026Third Party Advisory
- https://www.debian.org/security/2022/dsa-5034Issue Tracking, Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-49/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-50/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.