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TI-2021-03019 Aliases CVE-2021-4145GHSA-j9qg-fc9x-6r3r

NULL pointer dereference in QEMU

Priority LOW 29CWE-476Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 2 fixed, 4 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.

Summary

A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.

Why it matters now

EPSS 0.00387 32nd percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 2 fixed, 4 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 6.2.0—No fix listedCNA
  • QEMU Vendor— Affected qemu-kvm 6.2.0 Fixed in — No fix listed CNA

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:a:qemu:qemu:6.1.0:-:*:*:*:*:*:*6.1.0VulnerableQEMU
cpe:2.3:a:qemu:qemu:6.1.0:rc0:*:*:*:*:*:*6.1.0 rc0VulnerableQEMU
cpe:2.3:a:qemu:qemu:6.1.0:rc1:*:*:*:*:*:*6.1.0 rc1VulnerableQEMU
cpe:2.3:a:qemu:qemu:6.1.0:rc2:*:*:*:*:*:*6.1.0 rc2VulnerableQEMU
cpe:2.3:a:qemu:qemu:6.1.0:rc3:*:*:*:*:*:*6.1.0 rc3VulnerableQEMU
cpe:2.3:a:qemu:qemu:6.1.0:rc4:*:*:*:*:*:*6.1.0 rc4VulnerableQEMU
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*8.0VulnerableRed Hat
  • cpe:2.3:a:qemu:qemu:6.1.0:-:*:*:*:*:*:* Versions 6.1.0 Vulnerable ·QEMU
  • cpe:2.3:a:qemu:qemu:6.1.0:rc0:*:*:*:*:*:* Versions 6.1.0 rc0 Vulnerable ·QEMU
  • cpe:2.3:a:qemu:qemu:6.1.0:rc1:*:*:*:*:*:* Versions 6.1.0 rc1 Vulnerable ·QEMU
  • cpe:2.3:a:qemu:qemu:6.1.0:rc2:*:*:*:*:*:* Versions 6.1.0 rc2 Vulnerable ·QEMU
  • cpe:2.3:a:qemu:qemu:6.1.0:rc3:*:*:*:*:*:* Versions 6.1.0 rc3 Vulnerable ·QEMU
  • cpe:2.3:a:qemu:qemu:6.1.0:rc4:*:*:*:*:*:* Versions 6.1.0 rc4 Vulnerable ·QEMU
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:* Versions 8.0 Vulnerable ·Red Hat

Remediation

Red Hat 1 advisory

  • RHSA-2022:1759 Released 2022-05-10 · 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

Vendor assessments

Red Hat

Red Hat rating: Low. 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 OpenStack Platform 10 (Newton)AffectedNo fix planned: Out of support scope
Red Hat OpenStack Platform 13 (Queens)AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2022:1759
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2022:1759
Not affected: 2 products
  • Red Hat Enterprise Linux 8 Advanced Virtualization
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-4145
  2. 2026-10-03 Alias added: GHSA-j9qg-fc9x-6r3r

References

Patch 2

Advisory 2

Sources

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