CVE-2021-23969

NameCVE-2021-23969
DescriptionAs 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
ReferencesDLA-2575-1, DLA-2578-1, DSA-4862-1, DSA-4866-1
NVD severitymedium

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
firefox (PTS)sid88.0-1fixed
firefox-esr (PTS)stretch68.10.0esr-1~deb9u1vulnerable
stretch (security)78.10.0esr-1~deb9u1fixed
buster78.8.0esr-1~deb10u1fixed
buster (security)78.10.0esr-1~deb10u1fixed
bullseye, sid78.10.0esr-1fixed
thunderbird (PTS)stretch1:68.10.0-1~deb9u1vulnerable
stretch (security)1:78.10.0-1~deb9u1fixed
buster1:78.6.0-1~deb10u1vulnerable
buster (security)1:78.10.0-1~deb10u1fixed
bullseye, sid1:78.10.0-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
firefoxsource(unstable)86.0-1
firefox-esrsourcestretch78.8.0esr-1~deb9u1DLA-2575-1
firefox-esrsourcebuster78.8.0esr-1~deb10u1DSA-4862-1
firefox-esrsource(unstable)78.8.0esr-1
thunderbirdsourcestretch1:78.8.0-1~deb9u1DLA-2578-1
thunderbirdsourcebuster1:78.8.0-1~deb10u1DSA-4866-1
thunderbirdsource(unstable)1:78.8.0-1

Notes

https://www.mozilla.org/en-US/security/advisories/mfsa2021-07/#CVE-2021-23969
https://www.mozilla.org/en-US/security/advisories/mfsa2021-08/#CVE-2021-23969
https://www.mozilla.org/en-US/security/advisories/mfsa2021-09/#CVE-2021-23969

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