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, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
NVD severitylow
Debian Bugs985083

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
qemu (PTS)stretch1:2.8+dfsg-6+deb9u9fixed
stretch (security)1:2.8+dfsg-6+deb9u14fixed
buster, buster (security)1:3.1+dfsg-8+deb10u8fixed
bullseye1:5.2+dfsg-9fixed
sid1:5.2+dfsg-10fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
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

Search for package or bug name: Reporting problems