#VU17906 Race condition in Xen


Published: 2019-03-06 | Updated: 2020-07-28

Vulnerability identifier: #VU17906

Vulnerability risk: Low

CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-17341

CWE-ID: CWE-362

Exploitation vector: Local

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 a race condition when adding a passed-through PCI device to a domain after it was already started that results in the necessity to construct the IOMMU page tables on the fly therefore creating an attack window by allowing write access to the PV guests.

A local user can use a specially crafted application to perform write operations and alter such page tables without Xen auditing the changes that may result in execution of arbitrary code with hypervisor privileges.

Mitigation

Apply the following patches:

Vulnerable software versions

Xen: 4.7.0 - 4.11.1

External links
http://xenbits.xen.org/xsa/advisory-285.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.


Latest bulletins with this vulnerability


Race condition in xen (Alpine package)
Debian update for xen
Multiple vulnerabilities in Xen