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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (31.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Qemu
- Debian Linux — versions 10.0, 11.0
- Red Hat Enterprise Linux — versions 8.0
- Qemu — versions qemu-kvm 7.0.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- starlabs.sg/advisories/21-4207/ (Exploit, Third Party Advisory)
- www.debian.org/security/2022/dsa-5133 (vendor-advisory, Third Party Advisory)
- security.gentoo.org/glsa/202208-27 (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/09/msg00008.html (mailing-list, 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.