#VU40851 Input validation error in Fedora and Xen - CVE-2015-2752

Vulnerability identifier: #VU40851

Vulnerability risk: Medium

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

CVE-ID: CVE-2015-2752

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Fedora
Operating systems & Components / Operating system
Xen
Server applications / Virtualization software

Vendor: Fedoraproject
Xen Project

Description

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

The XEN_DOMCTL_memory_mapping hypercall in Xen 3.2.x through 4.5.x, when using a PCI passthrough device, is not preemptible, which allows local x86 HVM domain users to cause a denial of service (host CPU consumption) via a crafted request to the device model (qemu-dm).

Mitigation
Install update from vendor's website.

Vulnerable software versions

Fedora: 20 - 21

Xen: 4.3.0 - 21

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External links
https://lists.fedoraproject.org/pipermail/package-announce/2015-April/154574.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-April/154579.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-April/155198.html
https://lists.opensuse.org/opensuse-security-announce/2015-04/msg00014.html
https://lists.opensuse.org/opensuse-security-announce/2015-05/msg00018.html
https://www.securityfocus.com/bid/73448
https://www.securitytracker.com/id/1031994
https://xenbits.xen.org/xsa/advisory-125.html
https://security.gentoo.org/glsa/201504-04

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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.