Description
The fbld instruction emulation in Xen 3.3.x through 4.3.x does not use the correct variable for the source effective address, which allows local HVM guests to obtain hypervisor stack information by reading the values used by the 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 | 4.4.0-1 | — |
| Debian 13 | xen | 4.4.0-1 | — |
| Debian 12 | xen | 4.4.0-1 | — |
| Debian 7 | xen | 4.1.4-3+deb7u2 | DSA-3006-1 |
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-3006-1 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
- GLSA-201407-03 vendor-advisory
- SUSE-SU-2014:0446 vendor-advisory
- [oss-security] 20130930 Xen Security Advisory 66 (CVE-2013-4361) - Information leak through fbld instruction emulation mailing-list
- DSA-3006 vendor-advisory
- openSUSE-SU-2013:1636 vendor-advisory