Permissions, Privileges, and Access Controls in Xen - CVE-2015-2756
Published: April 1, 2015 / Updated: July 28, 2020
Vulnerability identifier: #VU32431
CSH Severity: Low
CVSS v4: 6.9 [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]
CVE-ID: CVE-2015-2756
CWE-ID: CWE-264
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local non-authenticated attacker to perform a denial of service (DoS) attack.
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 software
Xen
Gentoo Linux
Fedora
xen (Alpine package)
xen
Gentoo Linux
Fedora
xen (Alpine package)
xen
How to mitigate CVE-2015-2756
Install update from vendor's website.
xen (Alpine package) - update to 4.4.2-r0
xen - addressed in versions 4.4.2-2.fc21, 4.5.0-7.fc22
xen - addressed in versions 4.4.2-2.fc21, 4.5.0-7.fc22
External 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
- https://support.citrix.com/article/CTX206006