#VU48639 Off-by-one in Xen


Published: 2020-11-24

Vulnerability identifier: #VU48639

Vulnerability risk: Medium

CVSSv3.1: 6.2 [CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-193

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to an off-by-one error. A local user on the HVM or PVH system can run a specially crafted program on the guest OS, trigger an off-by-one error and execute arbitrary code on the hypervisor.

Note, the vulnerability exists due to incorrect patch of vulnerability #VU48638.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Xen: 4.2.0 - 4.14.0


External links
http://xenbits.xen.org/xsa/advisory-355.html


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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


Latest bulletins with this vulnerability