CVEvulnerability
CVE-2021-23969
4.3 MEDIUM
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- Status
- Modified
- Published
- 2021-02-26
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 4.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- CVSS 2.0 ([email protected])
- 4.3 MEDIUM — AV:N/AC:M/Au:N/C:P/I:N/A:N
Description
As specified in the W3C Content Security Policy draft, when creating a violation report, "User agents need to ensure that the source file is the URL requested by the page, pre-redirects. If that’s not possible, user agents need to strip the URL down to an origin to avoid unintentional leakage." Under certain types of redirects, Firefox incorrectly set the source file to be the destination of the redirects. This was fixed to be the redirect destination's origin. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.
Affected configurations
• mozilla firefox (< 86.0)
• mozilla firefox esr (< 78.8)
• mozilla thunderbird (< 78.8)
• debian debian linux 9.0
• debian debian linux 10.0
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1542194 Issue Tracking, Permissions Required, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html Mailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202104-09 Third Party Advisory
- https://security.gentoo.org/glsa/202104-10 Third Party Advisory
- https://www.debian.org/security/2021/dsa-4866 Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-07/ Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-08/ Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-09/ Release Notes, Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1542194 Issue Tracking, Permissions Required, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html Mailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202104-09 Third Party Advisory
- https://security.gentoo.org/glsa/202104-10 Third Party Advisory
- https://www.debian.org/security/2021/dsa-4866 Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-07/ Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-08/ Release Notes, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-09/ Release Notes, Vendor Advisory