SB2020121568 - Buffer overflow in Xen

Description

This security bulletin contains information about 1 vulnerability.

1) Buffer overflow (CVE-ID: CVE-2020-29568)

CWE-ID: CWE-119 - Memory corruption

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

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.

Remediation

Install update from vendor's website.

References

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