Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 86.0 |
| Mozilla | Firefox Esr | < 78.8 |
| Mozilla | Thunderbird | < 78.8 |
| Debian | Debian Linux | 9.0 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1542194Issue TrackingPermissions RequiredVendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00000.htmlMailing ListThird Party Advisory
- https://security.gentoo.org/glsa/202104-09Third Party Advisory
- https://security.gentoo.org/glsa/202104-10Third Party Advisory
- https://www.debian.org/security/2021/dsa-4866Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-07/Release NotesVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-08/Release NotesVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-09/Release NotesVendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1542194Issue TrackingPermissions RequiredVendor Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00000.htmlMailing ListThird Party Advisory
- https://security.gentoo.org/glsa/202104-09Third Party Advisory
- https://security.gentoo.org/glsa/202104-10Third Party Advisory
- https://www.debian.org/security/2021/dsa-4866Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-07/Release NotesVendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2021-08/Release NotesVendor Advisory
FAQ
What is CVE-2021-23969?
CVE-2021-23969 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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...
How severe is CVE-2021-23969?
CVE-2021-23969 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-23969?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird, Debian Debian Linux.