#VU32661 Information disclosure in Xen - CVE-2013-2076

Vulnerability identifier: #VU32661

Vulnerability risk: Low

CVSSv4.0: 1.9 [CVSS:4.0/AV:A/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2013-2076

CWE-ID: CWE-200

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a remote #AU# to gain access to sensitive information.

Xen 4.0.x, 4.1.x, and 4.2.x, when running on AMD64 processors, only save/restore the FOP, FIP, and FDP x87 registers in FXSAVE/FXRSTOR when an exception is pending, which allows one domain to determine portions of the state of floating point instructions of other domains, which can be leveraged to obtain sensitive information such as cryptographic keys, a similar vulnerability to CVE-2006-1056. NOTE: this is the documented behavior of AMD64 processors, but it is inconsistent with Intel processors in a security-relevant fashion that was not addressed by the kernels.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: 4.24

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External links
https://lists.opensuse.org/opensuse-security-announce/2014-03/msg00021.html
https://secunia.com/advisories/55082
https://security.gentoo.org/glsa/glsa-201309-24.xml
https://www.debian.org/security/2014/dsa-3006
https://www.openwall.com/lists/oss-security/2013/06/03/1

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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