CVE-2020-29479

An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the internal representation of the tree has special cases for the root node, because this node has no parent. Unfortunately, permissions were not checked for certain operations on the root node. Unprivileged guests can get and modify permissions, list, and delete the root node. (Deleting the whole xenstore tree is a host-wide denial of service.) Achieving xenstore write access is also possible. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.

CVSS v3.0 8.8 HIGH
CVSS v2.0 7.2 HIGH

8.8^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 2.0 / Impact : 6.0

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

7.2^/10

CVSS v2.0 : HIGH

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

Exploitability : 3.9 / Impact : 10.0

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

References

Link	Resource
https://xenbits.xenproject.org/xsa/advisory-353.html	Patch Vendor Advisory
https://www.debian.org/security/2020/dsa-4812	Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/	Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202107-30	Third Party Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

Configuration 3 (hide)

OR	cpe:2.3:o:fedoraproject:fedora:32:::::::*
	cpe:2.3:o:fedoraproject:fedora:33:::::::*

Information

Published : 2020-12-15 10:15

Updated : 2022-04-26 09:12

NVD link : CVE-2020-29479

Mitre link : CVE-2020-29479

JSON object : View

CWE

CWE-862

Missing Authorization

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Products Affected

debian

debian_linux

xen

xen

fedoraproject

fedora

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