Input validation error in Xen

1) Input validation error

EUVDB-ID: #VU32261

Risk: Low

CVSSv4.0: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2016-6259

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a local non-authenticated attacker to perform a denial of service (DoS) attack.

Xen 4.5.x through 4.7.x do not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allows local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Xen: 4.5.0 - 4.5.5

CPE2.3

• cpe:2.3:a:xen_project:xen:4.5.0:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:4.5.1:*:*:*:*:*:*:*
• cpe:2.3:a:xen_project:xen:4.5.2:*:*:*:*:*:*:*

External links

https://support.citrix.com/article/CTX214954
https://www.securityfocus.com/bid/92130
https://www.securitytracker.com/id/1036447
https://xenbits.xen.org/xsa/advisory-183.html
https://xenbits.xen.org/xsa/xsa183-4.6.patch
https://xenbits.xen.org/xsa/xsa183-unstable.patch

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.