CVE-2021-20263

NameCVE-2021-20263
DescriptionA flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a malicious user to elevate their privileges within the guest.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs985083

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
qemu (PTS)jessie, jessie (lts)1:2.1+dfsg-12+deb8u23fixed
stretch (security)1:2.8+dfsg-6+deb9u17fixed
stretch (lts), stretch1:2.8+dfsg-6+deb9u19fixed
buster1:3.1+dfsg-8+deb10u8fixed
buster (security)1:3.1+dfsg-8+deb10u12fixed
bullseye1:5.2+dfsg-11+deb11u3fixed
bullseye (security)1:5.2+dfsg-11+deb11u2fixed
bookworm1:7.2+dfsg-7+deb12u6fixed
trixie1:8.2.4+ds-1fixed
sid1:9.0.2+ds-1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
qemusourcejessie(not affected)
qemusourcestretch(not affected)
qemusourcebuster(not affected)
qemusource(unstable)1:5.2+dfsg-9985083

Notes

[buster] - qemu <not-affected> (Introduced in 5.2.0)
[stretch] - qemu <not-affected> (Introduced in 5.2.0)
https://bugzilla.redhat.com/show_bug.cgi?id=1933668
Introduced in: https://git.qemu.org/?p=qemu.git;a=commit;h=725ca3313a5b9cbef89eaa1c728567684f37990a
Fixed by: https://git.qemu.org/?p=qemu.git;a=commit;h=e586edcb410543768ef009eaa22a2d9dd4a53846
https://git.qemu.org/?p=qemu.git;a=commit;h=e586edcb410543768ef009eaa22a2d9dd4a53846
https://git.qemu.org/?p=qemu.git;a=commit;h=1e08f164e9fdc9528ad6990012301b9a04b0bc90
[jessie] - qemu <not-affected> (Introduced in 5.2.0)

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