Vulnerability identifier: #VU6843

Vulnerability risk: Low

CVSSv3.1: 5.2 [CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-8903

CWE-ID: CWE-264

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description
The vulnerability allows a local attacker to gain elevated privileges on the target system.

The weakness exists due to an error in the GNTTABOP_transfer operation. A local attacker can use a specially crafted IRET hypercall, gain write access to kernel page tables and execute arbitrary code on the host OS with elevated privileges.

Successful exploitation of the vulnerability results in privilege escalation.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: 4.5.0 - 4.8.1

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External links
http://xenbits.xen.org/xsa/advisory-213.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.