CVE-2015-5166
Use-after-free vulnerability in QEMU in Xen 4.5.x and earlier does not completely unplug emulated...
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.
Exploit likelihood
What each source reports
NVD Score used
7.2
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.
- Record
CVE-2015-5166- CVSS 2.0
- 7.2 High
AV:L/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-264
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2015-5166- Updated
- 2026-11-02
EUVDEUVD-2015-5173 No score
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.
- Record
EUVD-2015-5173- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gpg2-4ppg-g82w No score
Use-after-free vulnerability in QEMU in Xen 4.5.x and earlier does not completely unplug emulated...
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.
- Record
GHSA-gpg2-4ppg-g82w- Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2015-5166- Updated
- 2026-11-02
OSVDEBIAN-CVE-2015-5166 No score
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.
- Record
DEBIAN-CVE-2015-5166- Updated
- 2026-11-02
Show 5 moreShow less
OSVMGASA-2016-0098 No score
Updated xen packages fix security vulnerabilities
This xen update is based on upstream 4.5.2 maintenance release, and fixes the following security issues:
The vgic_v2_to_sgi function in arch/arm/vgic-v2.c in Xen 4.5.x, when running on ARM hardware with general interrupt controller (GIC) version 2, allows local guest users to cause a denial of service (host crash) by writing an invalid value to the GICD.SGIR register (CVE-2015-0268).
The ARM GIC distributor virtualization in Xen 4.4.x and 4.5.x allows local guests to cause a denial of service by causing a large number messages to be logged (CVE-2015-1563).
The emulation routines for unspecified X86 devices in Xen 3.2.x through 4.5.x does not properly initialize data, which allow local HVM guest users to obtain sensitive information via vectors involving an unsupported access size (CVE-2015-2044).
The HYPERVISOR_xen_version hypercall in Xen 3.2.x through 4.5.x does not properly initialize data structures, which allows local guest users to obtain sensitive information via unspecified vectors (CVE-2015-2045).
Xen 3.3.x through 4.5.x and the Linux kernel through 3.19.1 do not properly restrict access to PCI command registers, which might allow local 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 (CVE-2015-2150).
The x86 emulator in Xen 3.2.x through 4.5.x does not properly ignore segment overrides for instructions with register operands, which allows local guest users to obtain sensitive information, cause a denial of service (memory corruption), or possibly execute arbitrary code via unspecified vectors (CVE-2015-2151).
Xen 4.5.x and earlier enables certain default backends when emulating a VGA device for an x86 HVM guest qemu even when the configuration disables them, which allows local guest users to obtain access to the VGA console by (1) setting the DISPLAY environment variable, when compiled with SDL support, or connecting to the VNC server on (2) ::1 or (3) 127.0.0.1, when not compiled with SDL support (CVE-2015-2152).
Xen 4.3.x, 4.4.x, and 4.5.x, when using toolstack disaggregation, allows remote domains with partial management control to cause a denial of service (host lock) via unspecified domctl operations (CVE-2015-2751).
The XEN_DOMCTL_memory_mapping hypercall in Xen 3.2.x through 4.5.x, when using a PCI passthrough device, is not preemptable, 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) (CVE-2015-2752).
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 (CVE-2015-2756).
Heap-based buffer overflow in the PCNET controller in QEMU allows remote attackers to execute arbitrary code by sending a packet with TXSTATUS_STARTPACKET set and then a crafted packet with TXSTATUS_DEVICEOWNS set (CVE-2015-3209).
Stack-based buffer overflow in the xl command line utility in Xen 4.1.x through 4.5.x allows local guest administrators to gain privileges via a long configuration argument (CVE-2015-3259).
Xen 4.2.x through 4.5.x does not initialize certain fields, which allows certain remote service domains to obtain sensitive information from memory via a (1) XEN_DOMCTL_gettscinfo or (2) XEN_SYSCTL_getdomaininfolist request (CVE-2015-3340).
The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other…
- Record
MGASA-2016-0098- Updated
- 2026-11-02
OSVSUSE-SU-2015:1384-1 No score
security update for xen
This security update of Xen fixes the following issues:
- bsc#939712 (XSA-140): QEMU leak of uninitialized heap memory in rtl8139 device model (CVE-2015-5165)
- bsc#939709 (XSA-139): Use after free in QEMU/Xen block unplug protocol (CVE-2015-5166)
- Record
SUSE-SU-2015:1384-1- Updated
- 2026-11-02
OSVSUSE-SU-2015:1404-1 No score
security update for xen
This security update of Xen fixes the following issues:
- bsc#939712 (XSA-140): QEMU leak of uninitialized heap memory in rtl8139 device model (CVE-2015-5165)
- bsc#939709 (XSA-139): Use after free in QEMU/Xen block unplug protocol (CVE-2015-5166)
- Record
SUSE-SU-2015:1404-1- Updated
- 2026-11-02
OSVSUSE-SU-2015:1479-1 No score
Security update for xen
xen was updated to fix the following security issues:
- CVE-2015-5165: QEMU leak of uninitialized heap memory in rtl8139 device model (bsc#939712, XSA-140)
- CVE-2015-5166: Use after free in QEMU/Xen block unplug protocol (bsc#939709, XSA-139)
- CVE-2015-2751: Certain domctl operations could have be used to lock up the host (bsc#922709, XSA-127)
- CVE-2015-3259: xl command line config handling stack overflow (bsc#935634, XSA-137)
- CVE-2015-4164: DoS through iret hypercall handler (bsc#932996, XSA-136)
- CVE-2015-5154: Host code execution via IDE subsystem CD-ROM (bsc#938344)
- Record
SUSE-SU-2015:1479-1- Updated
- 2026-11-02
OSVSUSE-SU-2015:1479-2 No score
Security update for xen
xen was updated to fix the following security issues:
- CVE-2015-5165: QEMU leak of uninitialized heap memory in rtl8139 device model (bsc#939712, XSA-140)
- CVE-2015-5166: Use after free in QEMU/Xen block unplug protocol (bsc#939709, XSA-139)
- CVE-2015-2751: Certain domctl operations could have be used to lock up the host (bsc#922709, XSA-127)
- CVE-2015-3259: xl command line config handling stack overflow (bsc#935634, XSA-137)
- CVE-2015-4164: DoS through iret hypercall handler (bsc#932996, XSA-136)
- CVE-2015-5154: Host code execution via IDE subsystem CD-ROM (bsc#938344)
- Record
SUSE-SU-2015:1479-2- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
qemuDebian:12 |
before 1:2.4+dfsg-1a | 1:2.4+dfsg-1a |
qemuDebian:13 |
before 1:2.4+dfsg-1a | 1:2.4+dfsg-1a |
qemuDebian:14 |
before 1:2.4+dfsg-1a | 1:2.4+dfsg-1a |
xenDebian:12 |
before 4.4.0-1 | 4.4.0-1 |
xenDebian:13 |
before 4.4.0-1 | 4.4.0-1 |
xenDebian:14 |
before 4.4.0-1 | 4.4.0-1 |
xenMageia:5 |
before 4.5.2-1.5.mga5 | 4.5.2-1.5.mga5 |
xenSUSE:Linux Enterprise Desktop 12 |
before 4.4.2_10-22.8.1 | 4.4.2_10-22.8.1 |
xenSUSE:Linux Enterprise Software Development Kit 12 |
before 4.4.2_10-22.8.1 | 4.4.2_10-22.8.1 |
xenSUSE:Linux Enterprise Server 12 |
before 4.4.2_10-22.8.1 | 4.4.2_10-22.8.1 |
Show 10 moreShow less
| Package | Affected | Fixed |
|---|---|---|
xenSUSE:Linux Enterprise Server for SAP Applications 12 |
before 4.4.2_10-22.8.1 | 4.4.2_10-22.8.1 |
xenSUSE:Linux Enterprise Software Development Kit 11 SP4 |
before 4.4.2_12-23.1 | 4.4.2_12-23.1 |
xenSUSE:Linux Enterprise Desktop 11 SP4 |
before 4.4.2_12-23.1 | 4.4.2_12-23.1 |
xenSUSE:Linux Enterprise Server 11 SP4 |
before 4.4.2_12-23.1 | 4.4.2_12-23.1 |
xenSUSE:Linux Enterprise Server for SAP Applications 11 SP4 |
before 4.4.2_12-23.1 | 4.4.2_12-23.1 |
xenSUSE:Linux Enterprise Software Development Kit 11 SP3 |
before 4.2.5_12-15.1 | 4.2.5_12-15.1 |
xenSUSE:Linux Enterprise Desktop 11 SP3 |
before 4.2.5_12-15.1 | 4.2.5_12-15.1 |
xenSUSE:Linux Enterprise Server 11 SP3 |
before 4.2.5_12-15.1 | 4.2.5_12-15.1 |
xenSUSE:Linux Enterprise Server 11 SP3-TERADATA |
before 4.2.5_12-15.1 | 4.2.5_12-15.1 |
xenSUSE:Linux Enterprise Server for SAP Applications 11 SP3 |
before 4.2.5_12-15.1 | 4.2.5_12-15.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2015-5166 is a high vulnerability (CVSS 7.2) in Xen, published August 11, 2015. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.43%, the 37th percentile. Fixed in qemu 1:2.4+dfsg-1a.
References
lists.fedoraproject.org/pipermail/package-announce/2015-September/167820.html
lists.fedoraproject.org/pipermail/package-announce/2015-September/165373.html
lists.fedoraproject.org/pipermail/package-announce/2015-September/167792.html
securityfocus.com/bid/76152
securitytracker.com/id/1033175
xenbits.xen.org/xsa/advisory-139.html
Show 70 moreShow less
nvd.nist.gov/vuln/detail/CVE-2015-5166
github.com/advisories/GHSA-gpg2-4ppg-g82w
security-tracker.debian.org/tracker/CVE-2015-5166
advisories.mageia.org/MGASA-2016-0098.html
bugs.mageia.org/show_bug.cgi?id=16956
xenbits.xen.org/xsa/advisory-117.html
xenbits.xen.org/xsa/advisory-118.html
xenbits.xen.org/xsa/advisory-119.html
xenbits.xen.org/xsa/advisory-120.html
xenbits.xen.org/xsa/advisory-121.html
xenbits.xen.org/xsa/advisory-122.html
xenbits.xen.org/xsa/advisory-123.html
xenbits.xen.org/xsa/advisory-124.html
xenbits.xen.org/xsa/advisory-125.html
xenbits.xen.org/xsa/advisory-126.html
xenbits.xen.org/xsa/advisory-127.html
xenbits.xen.org/xsa/advisory-128.html
xenbits.xen.org/xsa/advisory-129.html
xenbits.xen.org/xsa/advisory-130.html
xenbits.xen.org/xsa/advisory-131.html
xenbits.xen.org/xsa/advisory-132.html
xenbits.xen.org/xsa/advisory-133.html
xenbits.xen.org/xsa/advisory-134.html
xenbits.xen.org/xsa/advisory-135.html
xenbits.xen.org/xsa/advisory-136.html
xenbits.xen.org/xsa/advisory-137.html
xenbits.xen.org/xsa/advisory-138.html
xenbits.xen.org/xsa/advisory-140.html
xenbits.xen.org/xsa/advisory-141.html
xenbits.xen.org/xsa/advisory-142.html
xenbits.xen.org/xsa/advisory-145.html
xenbits.xen.org/xsa/advisory-146.html
xenbits.xen.org/xsa/advisory-147.html
xenbits.xen.org/xsa/advisory-148.html
xenbits.xen.org/xsa/advisory-149.html
xenbits.xen.org/xsa/advisory-150.html
xenbits.xen.org/xsa/advisory-151.html
xenbits.xen.org/xsa/advisory-152.html
xenbits.xen.org/xsa/advisory-153.html
xenbits.xen.org/xsa/advisory-154.html
xenbits.xen.org/xsa/advisory-155.html
xenbits.xen.org/xsa/advisory-156.html
xenbits.xen.org/xsa/advisory-158.html
xenbits.xen.org/xsa/advisory-159.html
xenbits.xen.org/xsa/advisory-162.html
xenbits.xen.org/xsa/advisory-163.html
xenbits.xen.org/xsa/advisory-164.html
xenbits.xen.org/xsa/advisory-165.html
xenbits.xen.org/xsa/advisory-166.html
xenbits.xen.org/xsa/advisory-167.html
xenbits.xen.org/xsa/advisory-168.html
xenbits.xen.org/xsa/advisory-170.html
xenproject.org/downloads/xen-archives/xen-45-series/xen-451.html
xenproject.org/downloads/xen-archives/xen-45-series/xen-452.html
suse.com/support/update/announcement/2015/suse-su-20151384-1
bugzilla.suse.com/939709
bugzilla.suse.com/939712
suse.com/security/cve/CVE-2015-5165
suse.com/security/cve/CVE-2015-5166
suse.com/support/update/announcement/2015/suse-su-20151404-1
suse.com/support/update/announcement/2015/suse-su-20151479-1
bugzilla.suse.com/922709
bugzilla.suse.com/932996
bugzilla.suse.com/935634
bugzilla.suse.com/938344
suse.com/security/cve/CVE-2015-2751
suse.com/security/cve/CVE-2015-3259
suse.com/security/cve/CVE-2015-4164
suse.com/security/cve/CVE-2015-5154
suse.com/support/update/announcement/2015/suse-su-20151479-2
Left out here: the rest of 1 source description. The JSON record has them.