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TI-2021-03072 Aliases CVE-2021-4207GHSA-9p8r-v33g-4939

Race condition in QEMU

Priority LOW 36CWE-362Published · Updated

Key facts

Attack vector
Local
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 3 fixed, 5 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-120 and the CVSS impact.

Summary

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.

Why it matters now

EPSS 0.00402 34th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 2 advisoriesRed Hat: 3 fixed, 5 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—QEMUqemu-kvm 7.0.0—No fix listedCNA
  • QEMU Vendor— Affected qemu-kvm 7.0.0 Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*before 7.0.0VulnerableQEMU
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*8.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*8.0VulnerableRed Hat
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
  • cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:* Versions before 7.0.0 Vulnerable ·QEMU
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

Red Hat 2 advisories

  • RHSA-2022:5821 Released 2022-08-02 · Red Hat rating Moderate
    virt:rhel and virt-devel:rhel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.noarch::virt:rhel, SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.src::virt:rhel, hivex-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.aarch64::virt:rhel +47
    • Red Hat Enterprise Linux CRB (v. 8) SLOF-20210217-1.module+el8.6.0+14480+c0a3aa0f.src::virt-devel:rhel, hivex-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.i686::virt-devel:rhel, hivex-devel-1.3.18-23.module+el8.6.0+14480+c0a3aa0f.i686::virt-devel:rhel +47
  • RHSA-2022:5002 Released 2022-06-13 · Red Hat rating Moderate
    virt:av and virt-devel:av security and bug fix update
    • Advanced Virtualization for RHEL 8.4.0.EUS SLOF-20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9.noarch::virt:av, SLOF-20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9.src::virt-devel:av, SLOF-20200717-1.gite18ddad8.module+el8.4.0+8855+a9e237a9.src::virt:av +47

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8 Advanced VirtualizationAffectedNo fix yet
Red Hat OpenStack Platform 10 (Newton)AffectedNo fix planned: Out of support scope
Red Hat OpenStack Platform 13 (Queens)AffectedNo fix planned: Out of support scope
Advanced Virtualization for RHEL 8.4.0.EUSFixed RHSA-2022:5002
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2022:5821
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2022:5821
Not affected: 1 product
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-4207
  2. 2026-10-03 Alias added: GHSA-9p8r-v33g-4939

References

Exploit 1

Advisory 4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences