Use After Free in Mozilla Firefox
CVE-2021-38504
When interacting with an HTML input element's file picker dialog with webkitdirectory set, a use-after-free could have resulted, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
Vulnerability class: Use-After-Free
EPSS: 0.016 (73.1th percentile) — read the EPSS interpretation.
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.
Affected products
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Firefox_esr
- Mozilla Thunderbird — versions unspecified
- Debian Debian_linux — versions 9.0, 10.0, 11.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (Permissions Required, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@mozilla.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@mozilla.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2021-38504?
- CVE-2021-38504 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 8.8/10. Published 2021-12-08.
- How severe is CVE-2021-38504?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2021-38504 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.