CVE-2021-26933 Affecting xen package, versions [4.9.0,]


Severity

Recommended
0.0
medium
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.05% (18th percentile)

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  • Snyk IDSNYK-UNMANAGED-XEN-2383827
  • published26 Jan 2022
  • disclosed17 Feb 2021
  • creditUnknown

Introduced: 17 Feb 2021

CVE-2021-26933  (opens in a new tab)

How to fix?

There is no fixed version for xen.

Overview

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.

References

CVSS Scores

version 3.1