Vulnerability in Xen
CVE-2015-2756
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.
Published · last modified .
CVSS v2 metric
CVSS v2 base score 4.9 (Medium). Vector: AV:L/AC:L/Au:N/C:N/I:N/A:C. This CVE predates CVSS v3 and has no v3 score from NVD.
EPSS exploit prediction
EPSS: 0.004 (36.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Xen — versions 4.3.0, 4.3.1, 4.3.2
- Canonical Ubuntu Linux — versions 12.04, 14.04, 14.10
- Debian Linux — versions 7.0, 8.0
- Fedoraproject Fedora — versions 20, 21
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.securityfocus.com/bid/72577 (vdb-entry)
- security.gentoo.org/glsa/201504-04 (vendor-advisory)
- support.citrix.com/article/CTX206006
- www.debian.org/security/2015/dsa-3259 (vendor-advisory)
- lists.fedoraproject.org/pipermail/package-announce/2015-April/155198.html (vendor-advisory)
- lists.fedoraproject.org/pipermail/package-announce/2015-April/154574.html (vendor-advisory)
- support.citrix.com/article/CTX201145
- lists.nongnu.org/archive/html/qemu-devel/2015-03/msg06179.html (mailing-list)
- xenbits.xen.org/xsa/advisory-126.html (Vendor Advisory)
- lists.opensuse.org/opensuse-security-announce/2015-04/msg00014.html (vendor-advisory)
Frequently asked questions
- What is CVE-2015-2756?
- CVE-2015-2756 is a vulnerability in Xen, classified under CWE-264. Published 2015-04-01.
- Is CVE-2015-2756 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.