Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Xen | Xen | >= 4.4.0, <= 4.14.0 |
| Debian | Debian Linux | 10.0 |
| Fedoraproject | Fedora | 32 |
Related Weaknesses (CWE)
References
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202107-30Third Party Advisory
- https://www.debian.org/security/2020/dsa-4812Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-359.htmlPatchVendor Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202107-30Third Party Advisory
- https://www.debian.org/security/2020/dsa-4812Third Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-359.htmlPatchVendor Advisory
FAQ
What is CVE-2020-29571?
CVE-2020-29571 is a vulnerability with a CVSS score of 6.2 (MEDIUM). 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 ...
How severe is CVE-2020-29571?
CVE-2020-29571 has been rated MEDIUM with a CVSS base score of 6.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-29571?
Check the references section above for vendor advisories and patch information. Affected products include: Xen Xen, Debian Debian Linux, Fedoraproject Fedora.