Buffer overflow in Xen

1) Buffer overflow

EUVDB-ID: #VU52772

Risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-29568

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a local authenticated user to a crash the entire system.

An issue was discovered in Xen through 4.14.x. Some OSes (such as Linux, FreeBSD, and NetBSD) are processing watch events using a single thread. If the events are received faster than the thread is able to handle, they will get queued. As the queue is unbounded, a guest may be able to trigger an OOM in the backend. All systems with a FreeBSD, Linux, or NetBSD (any version) dom0 are vulnerable.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Xen: 4.0.0 - 4.15.0

External links

http://lists.debian.org/debian-lts-announce/2021/02/msg00018.html
http://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
http://www.debian.org/security/2021/dsa-4843
http://xenbits.xenproject.org/xsa/advisory-349.html

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.