#VU32261 Input validation error in Xen - CVE-2016-6259

Vulnerability identifier: #VU32261

Vulnerability 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

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

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

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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

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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.