CVE-2020-29571

An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered reads, and may hence end up de-referencing a NULL pointer. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. Only Arm systems may be vulnerable. Whether a system is vulnerable depends on the specific CPU. x86 systems are not vulnerable.

CVSS v3.0 6.2 MEDIUM
CVSS v2.0 4.9 MEDIUM

6.2^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 2.5 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

4.9^/10

CVSS v2.0 : MEDIUM

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

Exploitability : 3.9 / Impact : 6.9

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact COMPLETE

References

Link	Resource
https://xenbits.xenproject.org/xsa/advisory-359.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:*:*:*:*:*:*:arm:*

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 09:15

Updated : 2021-12-09 17:57

NVD link : CVE-2020-29571

Mitre link : CVE-2020-29571

JSON object : View

CWE

CWE-476

NULL Pointer Dereference

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Products Affected

debian

debian_linux

xen

xen

fedoraproject

fedora

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