Information disclosure in Mozilla Firefox
CVE-2021-43542
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
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:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.017 (76.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · 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/mfsa2021-53/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-54/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-52/ (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-2021-43542?
- CVE-2021-43542 is a medium-severity vulnerability in Mozilla Firefox, classified under Generation of Error Message Containing Sensitive Information. CVSS score: 6.5/10. Published 2021-12-08.
- How severe is CVE-2021-43542?
- Medium severity. CVSS v3 base score is 6.5 out of 10.