CVEvulnerability

CVE-2021-26933

5.5 MEDIUM Published 2021-02-17 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-02-17
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS 2.0 ([email protected])
2.1 LOW — AV:L/AC:L/Au:N/C:P/I:N/A:N

Description

An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.

Affected configurations

• xen xen (>= 4.9.0 <= 4.14.1) • fedoraproject fedora 32 • fedoraproject fedora 33 • debian debian linux 10.0

References