Description
The x86_emulate function in arch/x86/x86_emulate/x86_emulate.c in Xen 4.4.x and earlier does not properly check supervisor mode permissions, which allows local HVM users to cause a denial of service (guest crash) or gain guest kernel mode privileges via vectors involving an (1) HLT, (2) LGDT, (3) LIDT, or (4) LMSW instruction.
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 | 4.4.1-3 | — |
| Debian 13 | xen | 4.4.1-3 | — |
| Debian 12 | xen | 4.4.1-3 | — |
| Debian 7 | xen | 4.1.4-3+deb7u3 | DSA-3041-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | xen | 4.4.0-0ubuntu5.2 | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | xen | 4.7.0_12-1.3 | openSUSE-SU-2024:10196-1 |
Advisories 2
- DSA-3041-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10196-1 xen-4.7.0_12-1.3 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- openSUSE-SU-2014:1281 vendor-advisory
- FEDORA-2014-12000 vendor-advisory
- openSUSE-SU-2014:1279 vendor-advisory
- http://xenbits.xen.org/xsa/advisory-105.html
- http://support.citrix.com/article/CTX200218
- 1030888 vdb-entry
- FEDORA-2014-12036 vendor-advisory
- DSA-3041 vendor-advisory
- 61858 third-party-advisory
- 61890 third-party-advisory
- GLSA-201412-42 vendor-advisory
- 70057 vdb-entry