Vulnerability Details : CVE-2019-19338
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.
Products affected by CVE-2019-19338
- cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2019-19338
0.05%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 15 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2019-19338
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
2.1
|
LOW | AV:L/AC:L/Au:N/C:P/I:N/A:N |
3.9
|
2.9
|
NIST | |
|
5.5
|
MEDIUM | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
1.8
|
3.6
|
Red Hat, Inc. | |
|
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
1.8
|
3.6
|
NIST |
CWE ids for CVE-2019-19338
-
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.Assigned by:
- nvd@nist.gov (Primary)
- secalert@redhat.com (Secondary)
-
Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.Assigned by: secalert@redhat.com (Secondary)
References for CVE-2019-19338
-
https://software.intel.com/security-software-guidance/insights/deep-dive-intel-transactional-synchronization-extensions-intel-tsx-asynchronous-abort
Third Party Advisory
-
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-19338
1781514 – (CVE-2019-19338) CVE-2019-19338 Kernel: KVM: export MSR_IA32_TSX_CTRL to guest - incomplete fix for TAA (CVE-2019-11135)Issue Tracking;Patch;Third Party Advisory
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https://www.openwall.com/lists/oss-security/2019/12/10/3
oss-security - CVE-2019-19338 Kernel: KVM: export MSR_IA32_TSX_CTRL to guest - incomplete fix for TAA (CVE-2019-11135)Mailing List;Patch;Third Party Advisory
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