CVE-2020-25604

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 4.14.x. There is a race condition when migrating timers between x86 HVM vCPUs. When migrating timers of x86 HVM guests between its vCPUs, the locking model used allows for a second vCPU of the same guest (also operating on the timers) to release a lock that it didn't acquire. The most likely effect of the issue is a hang or crash of the hypervisor, i.e., a Denial of Service (DoS). All versions of Xen are affected. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only x86 HVM guests can leverage the vulnerability. x86 PV and PVH cannot leverage the vulnerability. Only guests with more than one vCPU can exploit the vulnerability.

References

http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html

https://lists.fedoraproject.org/archives/list/[email protected]/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/

https://lists.fedoraproject.org/archives/list/[email protected]/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/

https://lists.fedoraproject.org/archives/list/[email protected]/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/

https://security.gentoo.org/glsa/202011-06

https://www.debian.org/security/2020/dsa-4769

https://xenbits.xen.org/xsa/advisory-336.html

Details

Source: MITRE

Published: 2020-09-23

Updated: 2020-11-11

Type: CWE-362

Risk Information

CVSS v2

Base Score: 1.9

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

Impact Score: 2.9

Exploitability Score: 3.4

Severity: LOW

CVSS v3

Base Score: 4.7

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

Impact Score: 3.6

Exploitability Score: 1

Severity: MEDIUM

Vulnerable Software

Configuration 1

OR

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* versions up to 4.14.0 (inclusive)

Configuration 2

OR

cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

Tenable Plugins

View all (15 total)

IDNameProductFamilySeverity
150542SUSE SLES11 Security Update : xen (SUSE-SU-2020:14521-1)NessusSuSE Local Security Checks
medium
150180OracleVM 3.4 : xen (OVMSA-2021-0014)NessusOracleVM Local Security Checks
high
143873SUSE SLES12 Security Update : xen (SUSE-SU-2020:2787-1)NessusSuSE Local Security Checks
medium
143853SUSE SLES12 Security Update : xen (SUSE-SU-2020:2788-1)NessusSuSE Local Security Checks
medium
143805SUSE SLES12 Security Update : xen (SUSE-SU-2020:2822-1)NessusSuSE Local Security Checks
medium
143707SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2020:2791-1)NessusSuSE Local Security Checks
medium
143685SUSE SLES12 Security Update : xen (SUSE-SU-2020:2786-1)NessusSuSE Local Security Checks
medium
143637SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2020:2790-1)NessusSuSE Local Security Checks
medium
142854GLSA-202011-06 : Xen: Multiple vulnerabilitiesNessusGentoo Local Security Checks
high
141836Xen Migrating Timers Race condition DoS (XSA-336)NessusMisc.
medium
141278Fedora 31 : xen (2020-d46fe34349)NessusFedora Local Security Checks
medium
141270Fedora 33 : xen (2020-306b84fd07)NessusFedora Local Security Checks
medium
141168openSUSE Security Update : xen (openSUSE-2020-1608)NessusSuSE Local Security Checks
medium
141138Debian DSA-4769-1 : xen - security updateNessusDebian Local Security Checks
medium
141102Fedora 32 : xen (2020-f668e579be)NessusFedora Local Security Checks
medium