CVE-2021-4206
A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the…
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
A 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.
Timeline
ID reserved
By redhat
- 4 months later
· 4 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | High8.2 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.83% · top 42% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Weakness
Affected products
QEMU
- affected qemu-kvm 7.0.0
References (6)
- https://bugzilla.redhat.com/show_bug.cgi?id=2036998 (opens in a new tab)x_refsource_MISCx_transferred
- https://starlabs.sg/advisories/21-4206/ (opens in a new tab)x_refsource_MISCx_transferred
- DSA-5133 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- GLSA-202208-27 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- [debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security update (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- https://security.netapp.com/advisory/ntap-20250321-0010/ (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-4206)Record last updated .