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Fencer Intel
high 7.2

CVE-2015-5166 json

Use-after-free vulnerability in QEMU in Xen 4.5.x and earlier does not completely unplug emulated block devices, which allows local HVM gue…

published 2015-08-12 11 y ago modified 2026-06-17 4 mo ago also EUVD-2015-5173

cvss
7.2
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

Use-after-free vulnerability in QEMU in Xen 4.5.x and earlier does not completely unplug emulated block devices, which allows local HVM guest users to gain privileges by unplugging a block device twice.

Patch / fix

  • xen Debian 14, Debian 13, Debian 12 4.4.0-1
  • qemu Debian 14, Debian 13, Debian 12 1:2.4+dfsg-1a

debian advisories DEBIAN-CVE-2015-5166

  • xen SLES 11 SP3-TERADATA, SLES 11 SP3, SLED 11 SP3 +2 more 4.2.5_12-15.1
  • xen SLES for SAP 11 SP4, SLES 11 SP4, SLED 11 SP4 +1 more 4.4.2_12-23.1
  • xen SLES for SAP 12, SLES 12, SLED 12 +1 more 4.4.2_10-22.8.1

suse advisories SUSE-SU-2015:1479-2SUSE-SU-2015:1479-1SUSE-SU-2015:1404-1SUSE-SU-2015:1384-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-5166 updated cvss 2.9

Qemu: BlockBackend object use after free issue (XSA-139)

  • Red Hat Enterprise Linux 5 kvm, xen Red Hat Enterprise Linux 6 qemu-img, qemu-kvm, qemu-kvm-tools, qemu-guest-agent, qemu-guest-agent-win32 Red Hat Enterprise Linux 7 qemu-img, qemu-kvm, libcacard, qemu-kvm-rhev, qemu-kvm-tools, libcacard-tools, +2 more Red Hat Enterprise Linux OpenStack Platform 5 (Icehouse) qemu-kvm-rhev Red Hat Enterprise Linux OpenStack Platform 6 (Juno) qemu-kvm-rhev Red Hat Enterprise Linux OpenStack Platform 7 (Kilo) qemu-img-rhev, qemu-kvm-rhev, libcacard-rhev, qemu-kvm-tools-rhev, libcacard-devel-rhev, libcacard-tools-rhev, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-264 Permissions, Privileges, and Access Controls

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.