User Enumeration Affecting torvalds/linux package, versions [,5.5)


Severity

Recommended
0.0
medium
0
10

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

Threat Intelligence

EPSS
0.03% (9th percentile)

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  • Snyk IDSNYK-UNMANAGED-TORVALDSLINUX-3006694
  • published26 Jan 2022
  • disclosed13 Jul 2020
  • creditUnknown

Introduced: 13 Jul 2020

CVE-2019-19338  (opens in a new tab)
CWE-203  (opens in a new tab)

How to fix?

Upgrade torvalds/linux to version 5.5 or higher.

Overview

Affected versions of this package are vulnerable to User Enumeration. A flaw was found in the fix for CVE-2019-11135, in the Linux upstream kernel versions before 5.5 where, the way Intel CPUs handle speculative execution of instructions when a TSX Asynchronous Abort (TAA) error occurs. When a guest is running on a host CPU affected by the TAA flaw (TAA_NO=0), but is not affected by the MDS issue (MDS_NO=1), the guest was to clear the affected buffers by using a VERW instruction mechanism. But when the MDS_NO=1 bit was exported to the guests, the guests did not use the VERW mechanism to clear the affected buffers. This issue affects guests running on Cascade Lake CPUs and requires that host has 'TSX' enabled. Confidentiality of data is the highest threat associated with this vulnerability.

CVSS Base Scores

version 3.1