CVE-2021-4207: Buffer Overflow
First published: Tue Jan 04 2022(Updated: )
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.
Credit: secalert@redhat.com secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| QEMU qemu | <7.0.0 | |
| Redhat Enterprise Linux | =8.0 | |
| Redhat Enterprise Linux | =8.0 | |
| Debian Debian Linux | =10.0 | |
| Debian Debian Linux | =11.0 | |
| ubuntu/qemu | <1:6.2+dfsg-2ubuntu8 | 1:6.2+dfsg-2ubuntu8 |
| ubuntu/qemu | <1:6.2+dfsg-2ubuntu8 | 1:6.2+dfsg-2ubuntu8 |
| ubuntu/qemu | <1:2.11+dfsg-1ubuntu7.40 | 1:2.11+dfsg-1ubuntu7.40 |
| ubuntu/qemu | <1:4.2-3ubuntu6.23 | 1:4.2-3ubuntu6.23 |
| ubuntu/qemu | <1:6.0+dfsg-2 | 1:6.0+dfsg-2 |
| ubuntu/qemu | <1:6.2+dfsg-2ubuntu6.2 | 1:6.2+dfsg-2ubuntu6.2 |
| ubuntu/qemu | <1:6.2+dfsg-2ubuntu8 | 1:6.2+dfsg-2ubuntu8 |
| redhat/qemu-kvm | <7.0.0 | 7.0.0 |
| debian/qemu | <=1:3.1+dfsg-8+deb10u8 | 1:3.1+dfsg-8+deb10u11 1:5.2+dfsg-11+deb11u3 1:5.2+dfsg-11+deb11u2 1:7.2+dfsg-7+deb12u3 1:8.2.1+ds-1 |
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Reference Links
- https://bugzilla.redhat.com/show_bug.cgi?id=2036966
- https://starlabs.sg/advisories/21-4207/
- https://www.debian.org/security/2022/dsa-5133
- https://security.gentoo.org/glsa/202208-27
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
- https://launchpad.net/bugs/cve/CVE-2021-4207
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2070896
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2070895
- https://starlabs.sg/advisories/21-4207
- https://access.redhat.com/security/cve/CVE-2021-4207
- https://starlabs.sg/advisories/22-4207/
- https://access.redhat.com/security/cve/CVE-2022-4207
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2036966#c8
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2036966#c7
- https://starlabs.sg/advisories
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2036998
- https://gitlab.com/qemu-project/qemu/-/commit/9569f5cb
- https://access.redhat.com/errata/RHSA-2022:5002
- https://access.redhat.com/errata/RHSA-2022:5821
- https://access.redhat.com/security/cve/cve-2021-4207
- https://starlabs.sg/advisories/21/21-4207/
- https://gitlab.com/qemu-project/qemu/-/commit/9569f5cb5b4bffa9d3ebc8ba7da1e03830a9a895
- https://security-tracker.debian.org/tracker/CVE-2021-4207
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-4207
- https://ubuntu.com/security/notices/USN-5489-1
- https://nvd.nist.gov/vuln/detail/CVE-2021-4207
- https://git.qemu.org/?p=qemu.git;a=commit;h=9569f5cb5b4bffa9d3ebc8ba7da1e03830a9a895
- https://ubuntu.com/security/CVE-2021-4207
Frequently Asked Questions
What is the vulnerability ID for this flaw in the QXL display device emulation in QEMU?
The vulnerability ID is CVE-2021-4207.
What is the severity rating of CVE-2021-4207?
CVE-2021-4207 has a severity rating of 8.2 (high).
What software is affected by CVE-2021-4207?
QEMU qemu, Redhat Enterprise Linux (8.0), Debian Debian Linux (10.0, 11.0), and Ubuntu qemu (kinetic, lunar, bionic, focal, impish, jammy, mantic) are affected by CVE-2021-4207.
What is the description of CVE-2021-4207?
CVE-2021-4207 is a flaw in the QXL display device emulation in QEMU that can lead to a heap-based buffer overflow.
How can I fix CVE-2021-4207?
To fix CVE-2021-4207, update to version 7.0.0 of qemu-kvm (for Redhat) or update to the latest version of QEMU qemu, Redhat Enterprise Linux, Debian Debian Linux, or Ubuntu qemu.
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