CVE-2019-19338

2019-12-1008:18:14

redhat.com

access.redhat.com

6.5 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

2.1 Low

CVSS2

Access Vector

LOCAL

Access Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

NONE

AV:L/AC:L/Au:N/C:P/I:N/A:N

0.001 Low

EPSS

Percentile

22.3%

JSON

A flaw was found in the fix for CVE-2019-11135, 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.

Mitigation

Please refer to the Red Hat Knowledgebase Transactional Synchronization Extensions (TSX) Asynchronous Abort article (<https://access.redhat.com/solutions/tsx-asynchronousabort>) for mitigation instructions.