Permissions, Privileges, and Access Controls in Xen

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU32215

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2016-9382

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local authenticated user to execute arbitrary code.

Xen 4.0.x through 4.7.x mishandle x86 task switches to VM86 mode, which allows local 32-bit x86 HVM guest OS users to gain privileges or cause a denial of service (guest OS crash) by leveraging a guest operating system that uses hardware task switching and allows a new task to start in VM86 mode.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Xen: 4.0.0 - 4.0.4

CPE2.3

• cpe:2.3:a:xen_project:xen:4.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:4.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:4.0.2:*:*:*:*:*:*:*

External links

https://www.securityfocus.com/bid/94470
https://www.securitytracker.com/id/1037341
https://xenbits.xen.org/xsa/advisory-192.html
https://security.gentoo.org/glsa/201612-56
https://support.citrix.com/article/CTX218775

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.