Description
arch/x86/x86_emulate/x86_emulate.c in Xen 3.2.1 through 4.4.x does not properly check privileges, which allows local HVM guest users to gain privileges or cause a denial of service (crash) via a crafted (1) CALL, (2) JMP, (3) RETF, (4) LCALL, (5) LJMP, or (6) LRET far branch 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 | 4.4.1-4 | — |
| Debian 13 | xen | 4.4.1-4 | — |
| Debian 12 | xen | 4.4.1-4 | — |
| Debian 7 | xen | 4.1.4-3+deb7u4 | DSA-3140-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | xen | 4.4.1-0ubuntu0.14.04.2 | — |
Advisories 1
- DSA-3140-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- GLSA-201504-04 vendor-advisory
- 62672 third-party-advisory
- http://support.citrix.com/article/CTX201794
- http://support.citrix.com/article/CTX200288
- DSA-3140 vendor-advisory
- 62537 third-party-advisory
- openSUSE-SU-2015:0226 vendor-advisory
- 71151 vdb-entry
- http://xenbits.xen.org/xsa/advisory-110.html
- openSUSE-SU-2015:0256 vendor-advisory
- xen-cve20148595-priv-esc(98768) vdb-entry