Vulnerability in Mozilla Firefox
CVE-2021-23977
Firefox for Android suffered from a time-of-check-time-of-use vulnerability that allowed a malicious application to read sensitive data from application directories. Note: This issue is only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 86.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.009 (57.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · 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-2021-23977?
- CVE-2021-23977 is a medium-severity vulnerability in Mozilla Firefox, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 5.3/10. Published 2021-02-26.
- How severe is CVE-2021-23977?
- Medium severity. CVSS v3 base score is 5.3 out of 10.