Description
The compat_iret function in Xen 3.1 through 4.5 iterates the wrong way through a loop, which allows local 32-bit PV guest administrators to cause a denial of service (large loop and system hang) via a hypercall_iret call with EFLAGS.VM set.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | xen | 4.6.0-1 | — |
| Debian 13 | xen | 4.6.0-1 | — |
| Debian 12 | xen | 4.6.0-1 | — |
| Debian 8 | xen | 4.4.1-9+deb8u1 | DSA-3286-1 |
| Debian 7 | xen | 4.1.4-3+deb7u8 | DSA-3286-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | xen | 4.4.2-0ubuntu0.14.04.2 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | xen | 4.4.2_06-21.1 | SUSE-SU-2015:1042-1 |
| SLES 11 SP3 | xen | 4.2.5_12-15.1 | SUSE-SU-2015:1479-2, SUSE-SU-2015:1479-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 | xen | 4.4.2_06-21.1 | SUSE-SU-2015:1042-1 |
| SLES for SAP 11 SP3 | xen | 4.2.5_12-15.1 | SUSE-SU-2015:1479-1 |
Advisories 4
- DSA-3286-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2015:1042-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1479-2 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1479-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
References
- 75149 vdb-entry
- DSA-3286 vendor-advisory
- SUSE-SU-2015:1156 vendor-advisory
- SUSE-SU-2015:1643 vendor-advisory
- 1032569 vdb-entry
- SUSE-SU-2015:1206 vendor-advisory
- SUSE-SU-2015:1157 vendor-advisory
- http://support.citrix.com/article/CTX201145
- SUSE-SU-2015:1045 vendor-advisory
- http://xenbits.xen.org/xsa/advisory-136.html
- GLSA-201604-03 vendor-advisory
- SUSE-SU-2015:1042 vendor-advisory