{"cve":"CVE-2021-23977","nvd":{"published":"2021-02-26T03:15:14.213","modified":"2026-06-17T03:39:05.970","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N","score":5.3},"cwes":["CWE-367"],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=1684761","https://security.gentoo.org/glsa/202104-10","https://www.mozilla.org/security/advisories/mfsa2021-07/","https://bugzilla.mozilla.org/show_bug.cgi?id=1684761","https://security.gentoo.org/glsa/202104-10"],"products":["mozilla:firefox"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-23977","score":0.00881,"percentile":0.59147,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}