CVE-2021-26933

Severity

55%

Complexity

18%

Confidentiality

60%

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.

CVSS 3.1 Base Score 5.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

CVSS 2.0 Base Score 2.1. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:P/I:N/A:N).

Overview

First reported 4 years ago

2021-02-17 02:15:00

Last updated 3 years ago

2021-04-11 12:15:00

Affected Software

Fedora 32

32

References

http://xenbits.xen.org/xsa/advisory-364.html

http://xenbits.xen.org/xsa/advisory-364.html

Patch, Vendor Advisory

FEDORA-2021-4c819bf1ad

Mailing List, Third Party Advisory

FEDORA-2021-47f53a940a

Mailing List, Third Party Advisory

DSA-4888

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