#VU83584 NULL pointer dereference in Xen - CVE-2020-27675

Vulnerability identifier: #VU83584

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-27675

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in drivers/xen/events/events_base.c. A malicious guest can trigger a dom0 crash by sending events for a paravirtualized device while simultaneously performing its reconfiguration.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: All versions

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External links
https://xenbits.xen.org/xsa/advisory-331.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.