CVE-2021-4206

NameCVE-2021-4206
DescriptionA flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-3099-1, DSA-5133-1, ELA-705-1

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+deb9u17vulnerable
stretch (lts), stretch1:2.8+dfsg-6+deb9u19fixed
buster (security), buster, buster (lts)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+deb12u7fixed
trixie1:9.1.1+ds-5fixed
sid1:9.1.2+ds-1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
qemusourcejessie1:2.1+dfsg-12+deb8u23ELA-705-1
qemusourcestretch1:2.8+dfsg-6+deb9u18ELA-705-1
qemusourcebuster1:3.1+dfsg-8+deb10u9DLA-3099-1
qemusourcebullseye1:5.2+dfsg-11+deb11u2DSA-5133-1
qemusource(unstable)1:7.0+dfsg-1

Notes

https://bugzilla.redhat.com/show_bug.cgi?id=2036998
https://starlabs.sg/advisories/21/21-4206/
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/fa892e9abb728e76afcf27323ab29c57fb0fe7aa (v7.0.0-rc4)

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