CVE-2021-4207 Memory corruption in QEMU

What is CVE-2021-4207?

CVE-2021-4207 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 29 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-120, CWE-362

Which versions are affected by CVE-2021-4207?

It affects 3 products.

Products include Debian Debian Linux, Qemu Qemu, Redhat Enterprise Linux.

How do I fix CVE-2021-4207?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-4207 being exploited?

There is no known exploitation of CVE-2021-4207 in the wild and no public exploit code.

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All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-35155, AZL-9619, DEBIAN-CVE-2021-4207, GHSA-9p8r-v33g-4939, UBUNTU-CVE-2021-4207.