CVE-2020-29571 Null dereference in n/a

What is CVE-2020-29571?

CVE-2020-29571 is a medium-severity vulnerability in Debian Debian Linux, published on 15 Dec 2020. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered reads, and may hence end up de-referencing a NULL pointer. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. Only Arm systems may be vulnerable. Whether a system is vulnerable depends on the specific CPU. x86 systems are not vulnerable.

Weakness: CWE-476

Which versions are affected by CVE-2020-29571?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Xen Xen.

How do I fix CVE-2020-29571?

Apply the vendor's patch.

Is CVE-2020-29571 being exploited?

There is no known exploitation of CVE-2020-29571 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 ALPINE-CVE-2020-29571, DEBIAN-CVE-2020-29571, GHSA-26rg-mq58-rxvm, UBUNTU-CVE-2020-29571.