CVE-2018-12893

medium
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Description

An issue was discovered in Xen through 4.10.x. One of the fixes in XSA-260 added some safety checks to help prevent Xen livelocking with debug exceptions. Unfortunately, due to an oversight, at least one of these safety checks can be triggered by a guest. A malicious PV guest can crash Xen, leading to a Denial of Service. All Xen systems which have applied the XSA-260 fix are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only x86 PV guests can exploit the vulnerability. x86 HVM and PVH guests cannot exploit the vulnerability. An attacker needs to be able to control hardware debugging facilities to exploit the vulnerability, but such permissions are typically available to unprivileged users.

References

http://www.openwall.com/lists/oss-security/2018/06/27/11

http://www.securityfocus.com/bid/104572

http://www.securitytracker.com/id/1041202

http://xenbits.xen.org/xsa/advisory-265.html

https://bugzilla.redhat.com/show_bug.cgi?id=1590979

https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html

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

https://support.citrix.com/article/CTX235748

https://www.debian.org/security/2018/dsa-4236

Details

Source: MITRE

Published: 2018-07-02

Updated: 2019-10-03

Risk Information

CVSS v2

Base Score: 2.1

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

Impact Score: 2.9

Exploitability Score: 3.9

Severity: LOW

CVSS v3

Base Score: 6.5

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

Impact Score: 4

Exploitability Score: 2

Severity: MEDIUM

Vulnerable Software

Configuration 1

OR

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:x86 versions up to 4.10.0 (inclusive)

Configuration 2

OR

cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

Tenable Plugins

View all (18 total)

IDNameProductFamilySeverity
123224openSUSE Security Update : xen (openSUSE-2019-533)NessusSuSE Local Security Checks
critical
120682Fedora 28 : xen (2018-a7862a75f5)NessusFedora Local Security Checks
critical
120050SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2018:1981-1)NessusSuSE Local Security Checks
critical
118892Debian DLA-1577-1 : xen security updateNessusDebian Local Security Checks
high
118506GLSA-201810-06 : Xen: Multiple vulnerabilities (Foreshadow) (Meltdown) (Spectre)NessusGentoo Local Security Checks
critical
118277SUSE SLES12 Security Update : xen (SUSE-SU-2018:2081-2)NessusSuSE Local Security Checks
critical
112147SUSE SLES11 Security Update : xen (SUSE-SU-2018:2528-1) (Foreshadow) (Meltdown) (Spectre)NessusSuSE Local Security Checks
high
111565openSUSE Security Update : xen (openSUSE-2018-803)NessusSuSE Local Security Checks
critical
111433SUSE SLES12 Security Update : xen (SUSE-SU-2018:2081-1)NessusSuSE Local Security Checks
critical
111418openSUSE Security Update : xen (openSUSE-2018-766)NessusSuSE Local Security Checks
critical
111380Xen Project x86 Debug Exception Handling Local DoS (XSA-265)NessusMisc.
medium
111378Citrix XenServer Multiple Vulnerabilities (CTX235748)NessusMisc.
medium
111371SUSE SLES12 Security Update : xen (SUSE-SU-2018:2069-1)NessusSuSE Local Security Checks
high
111348SUSE SLED12 / SLES12 Security Update : xen (SUSE-SU-2018:2059-1)NessusSuSE Local Security Checks
critical
111346SUSE SLES12 Security Update : xen (SUSE-SU-2018:2056-1)NessusSuSE Local Security Checks
high
111261SUSE SLES11 Security Update : xen (SUSE-SU-2018:2037-1)NessusSuSE Local Security Checks
high
111236Fedora 27 : xen (2018-1a467757ce)NessusFedora Local Security Checks
critical
110787Debian DSA-4236-1 : xen - security updateNessusDebian Local Security Checks
critical