Vulnerability in Mozilla Firefox
CVE-2021-38509
Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
EPSS: 0.016 (73.6th percentile) — read the EPSS interpretation.
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.
Affected products
- Mozilla Firefox — versions unspecified
- Mozilla Firefox Esr — versions unspecified
- Mozilla Firefox_esr
- Mozilla Thunderbird — versions unspecified
- Debian Debian_linux — versions 9.0, 10.0, 11.0
Weakness classification (CWE)
References
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (x_refsource_MISC, Vendor Advisory)
- security@mozilla.org (Permissions Required, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- security@mozilla.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- security@mozilla.org (vendor-advisory, Mailing List, Third Party Advisory, x_refsource_DEBIAN)
- security@mozilla.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- security@mozilla.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2021-38509?
- CVE-2021-38509 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-2021-38509?
- Medium severity. CVSS v3 base score is 4.3 out of 10.