Auth bypass in Mozilla Firefox
CVE-2021-23975
The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes. When this function was invoked we incorrectly called the sizeof function, instead of using the API method that checks for invalid pointers. This vulnerability affects Firefox < 86.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.010 (61.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 61.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: -0.000
Affected products
- Mozilla Firefox — versions < 86
Weakness classification (CWE)
References
- www.mozilla.org/security/advisories/mfsa2021-07/ (Release Notes, Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking, Vendor Advisory)
- security.gentoo.org/glsa/202104-10 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-23975?
- CVE-2021-23975 is a medium-severity vulnerability in Mozilla Firefox, classified under Missing Authorization. CVSS score: 6.5/10. Published 2021-02-26.
- How severe is CVE-2021-23975?
- Medium severity. CVSS v3 base score is 6.5 out of 10.