CVE-2021-4207
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.2 HIGHCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.40% probability · 34th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-362, CWE-120
- Affected
- qemu/qemu · redhat/enterprise linux · debian/debian linux
- Source
- secalert@redhat.com
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2036966Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202208-27Third Party Advisory
- https://starlabs.sg/advisories/21-4207/Exploit, Third Party Advisory
- https://www.debian.org/security/2022/dsa-5133Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2036966Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202208-27Third Party Advisory
- https://security.netapp.com/advisory/ntap-20250321-0009/
- https://starlabs.sg/advisories/21-4207/Exploit, Third Party Advisory
- https://www.debian.org/security/2022/dsa-5133Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.