| Name | CVE-2021-4207 |
| Description | A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values `cursor->header.width` and `cursor->header.height` can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. A malicious privileged guest user could use this flaw to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-3099-1, DSA-5133-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| qemu (PTS) | bullseye | 1:5.2+dfsg-11+deb11u3 | fixed |
| bullseye (security) | 1:5.2+dfsg-11+deb11u2 | fixed |
| bookworm | 1:7.2+dfsg-7+deb12u7 | fixed |
| sid, trixie | 1:9.1.2+ds-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| qemu | source | buster | 1:3.1+dfsg-8+deb10u9 | | DLA-3099-1 | |
| qemu | source | bullseye | 1:5.2+dfsg-11+deb11u2 | | DSA-5133-1 | |
| qemu | source | (unstable) | 1:7.0+dfsg-1 | | | |
Notes
https://bugzilla.redhat.com/show_bug.cgi?id=2036966
https://starlabs.sg/advisories/21/21-4207/
Fixed by: https://gitlab.com/qemu-project/qemu/-/commit/9569f5cb5b4bffa9d3ebc8ba7da1e03830a9a895 (v7.0.0-rc4)