CVE-2020-29480

low
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. Neither xenstore implementation does any permission checks when reporting a xenstore watch event. A guest administrator can watch the root xenstored node, which will cause notifications for every created, modified, and deleted key. A guest administrator can also use the special watches, which will cause a notification every time a domain is created and destroyed. Data may include: number, type, and domids of other VMs; existence and domids of driver domains; numbers of virtual interfaces, block devices, vcpus; existence of virtual framebuffers and their backend style (e.g., existence of VNC service); Xen VM UUIDs for other domains; timing information about domain creation and device setup; and some hints at the backend provisioning of VMs and their devices. The watch events do not contain values stored in xenstore, only key names. A guest administrator can observe non-sensitive domain and device lifecycle events relating to other guests. This information allows some insight into overall system configuration (including the number and general nature of other guests), and configuration of other guests (including the number and general nature of other guests' devices). This information might be commercially interesting or might make other attacks easier. There is not believed to be exposure of sensitive data. Specifically, there is no exposure of VNC passwords, port numbers, pathnames in host and guest filesystems, cryptographic keys, or within-guest data.

References

https://xenbits.xenproject.org/xsa/advisory-115.html

https://www.debian.org/security/2020/dsa-4812

https://lists.fedoraproject.org/archives/list/[email protected]/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/

https://lists.fedoraproject.org/archives/list/[email protected]/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/

Details

Source: MITRE

Published: 2020-12-15

Updated: 2021-07-21

Type: CWE-203

Risk Information

CVSS v2

Base Score: 2.1

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

Impact Score: 2.9

Exploitability Score: 3.9

Severity: LOW

CVSS v3

Base Score: 2.3

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

Impact Score: 1.4

Exploitability Score: 0.8

Severity: LOW

Tenable Plugins

View all (14 total)

IDNameProductFamilySeverity
150656SUSE SLES11 Security Update : xen (SUSE-SU-2020:14578-1)NessusSuSE Local Security Checks
high
150180OracleVM 3.4 : xen (OVMSA-2021-0014)NessusOracleVM Local Security Checks
high
145360openSUSE Security Update : xen (openSUSE-2020-2313)NessusSuSE Local Security Checks
high
145322openSUSE Security Update : xen (openSUSE-2020-2331)NessusSuSE Local Security Checks
high
144755Xen xenstore watch notification Information Disclosure (XSA-115)NessusMisc.
low
144637SUSE SLES12 Security Update : xen (SUSE-SU-2020:3945-1)NessusSuSE Local Security Checks
high
144613Fedora 32 : xen (2020-df772b417b)NessusFedora Local Security Checks
high
144611Fedora 33 : xen (2020-64859a826b)NessusFedora Local Security Checks
high
144580SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2020:3915-1)NessusSuSE Local Security Checks
high
144576SUSE SLES12 Security Update : xen (SUSE-SU-2020:3914-1)NessusSuSE Local Security Checks
high
144570SUSE SLES12 Security Update : xen (SUSE-SU-2020:3913-1)NessusSuSE Local Security Checks
high
144492SUSE SLES12 Security Update : xen (SUSE-SU-2020:3880-1)NessusSuSE Local Security Checks
medium
144476SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2020:3881-1)NessusSuSE Local Security Checks
high
144322Debian DSA-4812-1 : xen - security updateNessusDebian Local Security Checks
high