CVE-2018-15468

medium
New! CVE Severity Now Using CVSS v3

The calculated severity for CVEs has been updated to use CVSS v3 by default. CVEs that do not have a CVSS v3 score will fall back CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Description

An issue was discovered in Xen through 4.11.x. The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service.

References

http://xenbits.xen.org/xsa/advisory-269.html

https://security.gentoo.org/glsa/201810-06

Details

Source: MITRE

Published: 2018-08-17

Updated: 2019-10-03

Type: CWE-863

Risk Information

CVSS v2

Base Score: 4.9

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

Impact Score: 6.9

Exploitability Score: 3.9

Severity: MEDIUM

CVSS v3

Base Score: 6

Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H

Impact Score: 4

Exploitability Score: 1.5

Severity: MEDIUM

Vulnerable Software

Configuration 1

OR

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* versions up to 4.11.0 (inclusive)

Tenable Plugins

View all (12 total)

IDNameProductFamilySeverity
140019OracleVM 3.4 : xen (OVMSA-2020-0039) (Bunker Buster) (Foreshadow) (MDSUM/RIDL) (MFBDS/RIDL/ZombieLoad) (MLPDS/RIDL) (MSBDS/Fallout) (Meltdown) (POODLE) (Spectre)NessusOracleVM Local Security Checks
critical
123167openSUSE Security Update : xen (openSUSE-2019-1046) (Foreshadow)NessusSuSE Local Security Checks
high
120490Fedora 28 : xen (2018-683dfde81a) (Foreshadow)NessusFedora Local Security Checks
medium
120196SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2018:4300-1) (Foreshadow)NessusSuSE Local Security Checks
high
119951openSUSE Security Update : xen (openSUSE-2018-1624) (Foreshadow)NessusSuSE Local Security Checks
high
119277OracleVM 3.4 : xen (OVMSA-2018-0282) (Foreshadow) (Spectre)NessusOracleVM Local Security Checks
medium
118563openSUSE Security Update : xen (openSUSE-2018-1331) (Foreshadow)NessusSuSE Local Security Checks
critical
118506GLSA-201810-06 : Xen: Multiple vulnerabilities (Foreshadow) (Meltdown) (Spectre)NessusGentoo Local Security Checks
critical
118491SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2018:3490-1) (Foreshadow)NessusSuSE Local Security Checks
critical
118351SUSE SLES12 Security Update : xen (SUSE-SU-2018:3332-1)NessusSuSE Local Security Checks
critical
112234Fedora 27 : xen (2018-915602df63) (Foreshadow)NessusFedora Local Security Checks
medium
112157Xen Project MSR_DEBUGCTL 'Branch Trace Store' DoS (XSA-269)NessusMisc.
medium