CVE-2015-2756

Severity: medium (CVSS 4.9 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2015-04-01 · updated 2026-06-17
Weakness: CWE-264

Description

QEMU, as used in Xen 3.3.x through 4.5.x, does not properly restrict access to PCI command registers, which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device, which triggers an Unsupported Request (UR) response.

Affected products

Canonical Ubuntu Linux: 12.04, 14.04, 14.10, 15.04
Debian Linux: 7.0, 8.0
Fedoraproject Fedora: 20, 21
xen: 4.3.0, 4.3.1, 4.3.2, 4.4.0, 4.4.1, 4.5.0

References

http://lists.fedoraproject.org/pipermail/package-announce/2015-April/154574.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/154579.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155198.html
http://lists.nongnu.org/archive/html/qemu-devel/2015-03/msg06179.html
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00014.html
http://support.citrix.com/article/CTX201145
http://www.debian.org/security/2015/dsa-3259
http://www.securityfocus.com/bid/72577
http://www.securitytracker.com/id/1031998
http://www.ubuntu.com/usn/USN-2608-1
http://xenbits.xen.org/xsa/advisory-126.html
https://security.gentoo.org/glsa/201504-04

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