CVE-2021-20255 Denial of service in QEMU

What is CVE-2021-20255?

CVE-2021-20255 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 9 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Weakness: CWE-674, CWE-835

Which versions are affected by CVE-2021-20255?

It affects 2 products.

Products include Debian Debian Linux, Qemu Qemu.

How do I fix CVE-2021-20255?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-20255 being exploited?

There is no known exploitation of CVE-2021-20255 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-35149, AZL-6829, DEBIAN-CVE-2021-20255, GHSA-v6w7-gq3g-fwvm, UBUNTU-CVE-2021-20255.