Vulnerability in Mozilla Firefox
CVE-2021-23984
A malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.
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: 0.011 (64.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 64.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000
Affected products
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Firefox Esr
- Mozilla Thunderbird — versions unspecified
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.mozilla.org/security/advisories/mfsa2021-10/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-12/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2021-11/ (Vendor Advisory)
- bugzilla.mozilla.org/show_bug.cgi (Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-23984?
- CVE-2021-23984 is a medium-severity vulnerability in Mozilla Firefox, classified under Authentication Bypass by Spoofing. CVSS score: 6.5/10. Published 2021-03-31.
- How severe is CVE-2021-23984?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-23984 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.