CVEvulnerability

CVE-2020-29571

6.2 MEDIUM Published 2020-12-15 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-12-15
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
6.2 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 ([email protected])
4.9 MEDIUM — AV:L/AC:L/Au:N/C:N/I:N/A:C
Weaknesses
CWE-476

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.

Affected configurations

• xen xen (>= 4.4.0 <= 4.14.0) • debian debian linux 10.0 • fedoraproject fedora 32 • fedoraproject fedora 33

Related

Weakness · CWE (1)

  • CWE-476 NULL Pointer Dereference weakness

References