#VU33948 Input validation error in Xen - CVE-2012-0218

Vulnerability identifier: #VU33948

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2012-0218

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

Xen 3.4, 4.0, and 4.1, when the guest OS has not registered a handler for a syscall or sysenter instruction, does not properly clear a flag for exception injection when injecting a General Protection Fault, which allows local PV guest OS users to cause a denial of service (guest crash) by later triggering an exception that would normally be handled within Xen.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: 4.24

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External links
https://lists.xen.org/archives/html/xen-announce/2012-06/msg00003.html
https://secunia.com/advisories/55082
https://security.gentoo.org/glsa/glsa-201309-24.xml
https://www.debian.org/security/2012/dsa-2501

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.