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.
Advisories
Source ID Title
Debian DSA Debian DSA DSA-4812-1 xen security update
EUVD EUVD EUVD-2020-21933 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.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2024-08-04T16:55:10.337Z

Reserved: 2020-12-04T00:00:00

Link: CVE-2020-29571

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2020-12-15T17:15:14.817

Modified: 2024-11-21T05:24:13.790

Link: CVE-2020-29571

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.