Vulnerability in Mozilla Firefox
CVE-2021-38506
Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
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: 0.015 (72.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000
Affected products
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Firefox Esr
- Mozilla Thunderbird — versions unspecified
- Debian Linux — versions 9.0, 10.0, 11.0
Weakness classification (CWE)
References
- www.mozilla.org/security/advisories/mfsa2021-49/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-50/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-48/ (Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking, Vendor Advisory)
- www.debian.org/security/2021/dsa-5026 (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/12/msg00030.html (mailing-list, Mailing List, Third Party Advisory)
- www.debian.org/security/2022/dsa-5034 (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/01/msg00001.html (mailing-list, Mailing List, Third Party Advisory)
- security.gentoo.org/glsa/202202-03 (vendor-advisory, Third Party Advisory)
- security.gentoo.org/glsa/202208-14 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-38506?
- CVE-2021-38506 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Rendered UI Layers or Frames (Clickjacking). CVSS score: 4.3/10. Published 2021-12-08.
- How severe is CVE-2021-38506?
- Medium severity. CVSS v3 base score is 4.3 out of 10.