Vulnerability identifier: #VU49943

Vulnerability risk: Low

CVSSv3.1: 7.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-29040

CWE-ID: CWE-193

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a local authenticated user to execute arbitrary code.

An issue was discovered in Xen through 4.14.x allowing x86 HVM guest OS users to cause a denial of service (stack corruption), cause a data leak, or possibly gain privileges because of an off-by-one error. NOTE: this issue is caused by an incorrect fix for CVE-2020-27671.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: 4.0.0 - 4.14.1

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External links
http://www.openwall.com/lists/oss-security/2021/01/19/4
http://xenbits.xen.org/xsa/advisory-355.html
http://xenbits.xen.org/xsa/advisory-355.html

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.