CVE-2021-23969

3Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackepss 1.2%

exploitation probability

1.2%top 33% of all CVEs

observed exploitation

nono source reports it

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 products

Mozilla · Firefox Mozilla · Firefox ESR Mozilla · Thunderbird

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1542194 https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html https://security.gentoo.org/glsa/202104-09 https://security.gentoo.org/glsa/202104-10 https://www.debian.org/security/2021/dsa-4866 https://www.mozilla.org/security/advisories/mfsa2021-07/https://www.mozilla.org/security/advisories/mfsa2021-08/https://www.mozilla.org/security/advisories/mfsa2021-09/