Buffer overflow in Qemu
CVE-2021-4207
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.
Vulnerability class: Race Condition
EPSS: 0.004 (32.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Qemu
- Debian Debian_linux — versions 10.0, 11.0
- Redhat Enterprise_linux — versions 8.0
- N/a Qemu — versions qemu-kvm 7.0.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- secalert@redhat.com (Third Party Advisory, x_refsource_MISC, Issue Tracking)
- secalert@redhat.com (Exploit, Third Party Advisory, x_refsource_MISC)
- secalert@redhat.com (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
- secalert@redhat.com (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- secalert@redhat.com (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2021-4207?
- CVE-2021-4207 is a high-severity vulnerability in Qemu, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 8.2/10. Published 2022-04-29.
- How severe is CVE-2021-4207?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2021-4207 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.