CVE-2021-4206
Publication date 29 April 2022
Last updated 9 June 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| qemu | 26.04 LTS resolute |
Fixed 1:6.2+dfsg-2ubuntu8
|
| 25.10 questing |
Fixed 1:6.2+dfsg-2ubuntu8
|
|
| 24.04 LTS noble |
Fixed 1:6.2+dfsg-2ubuntu8
|
|
| 22.04 LTS jammy |
Fixed 1:6.2+dfsg-2ubuntu6.2
|
|
| 20.04 LTS focal |
Fixed 1:4.2-3ubuntu6.23
|
|
| 18.04 LTS bionic |
Fixed 1:2.11+dfsg-1ubuntu7.40
|
|
| 16.04 LTS xenial |
Fixed 1:2.5+dfsg-5ubuntu10.51+esm4
|
|
| 14.04 LTS trusty |
Fixed 2.0.0+dfsg-2ubuntu1.47+esm6
|
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| Package | Patch details |
|---|---|
| qemu |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
8.2 · High
|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | High |
| User interaction | None |
| Scope | Changed |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
References
Related Ubuntu Security Notices (USN)
- USN-5489-1
- QEMU vulnerabilities
- 21 June 2022
- USN-8412-1
- QEMU vulnerabilities
- 9 June 2026