Privilege Escalation Affecting xen package, versions [4.0.0,]


Severity

Recommended
0.0
high
0
10

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

Threat Intelligence

EPSS
0.05% (17th percentile)

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  • Snyk IDSNYK-UNMANAGED-XEN-2383966
  • published26 Jan 2022
  • disclosed8 Sept 2021
  • creditUnknown

Introduced: 8 Sep 2021

CVE-2021-28701  (opens in a new tab)
CWE-269  (opens in a new tab)

How to fix?

There is no fixed version for xen.

Overview

Affected versions of this package are vulnerable to Privilege Escalation. Another race in XENMAPSPACE_grant_table handling Guests are permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.

References

CVSS Scores

version 3.1