Auth bypass in Mozilla Firefox
CVE-2021-29961
When styling and rendering an oversized `<select>` element, Firefox did not apply correct clipping which allowed an attacker to paint over the user interface. This vulnerability affects Firefox < 89.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.008 (53.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000
Affected products
- Mozilla Firefox — versions unspecified
Weakness classification (CWE)
References
- www.mozilla.org/security/advisories/mfsa2021-23/ (Release Notes, Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Issue Tracking, Broken Link, Vendor Advisory)
- security.gentoo.org/glsa/202107-09 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-29961?
- CVE-2021-29961 is a medium-severity vulnerability in Mozilla Firefox, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2021-06-24.
- How severe is CVE-2021-29961?
- Medium severity. CVSS v3 base score is 4.3 out of 10.