CVE-2020-29571

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.

Category

6.2
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.06%
Vendor Advisory debian.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory gentoo.org Vendor Advisory xenproject.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://xenbits.xenproject.org/xsa/advisory-359.html patch vendor advisory
https://www.debian.org/security/2020/dsa-4812 third party advisory vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/ vendor advisory
https://security.gentoo.org/glsa/202107-30 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-29571?
CVE-2020-29571 has been scored as a medium severity vulnerability.
How to fix CVE-2020-29571?
To fix CVE-2020-29571, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-29571 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2020-29571 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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