Description
Xen 4.0.x, 4.1.x, and 4.2.x, when running on AMD64 processors, only save/restore the FOP, FIP, and FDP x87 registers in FXSAVE/FXRSTOR when an exception is pending, which allows one domain to determine portions of the state of floating point instructions of other domains, which can be leveraged to obtain sensitive information such as cryptographic keys, a similar vulnerability to CVE-2006-1056. NOTE: this is the documented behavior of AMD64 processors, but it is inconsistent with Intel processors in a security-relevant fashion that was not addressed by the kernels.
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 | 4.2.2-1 | — |
| Debian 13 | xen | 4.2.2-1 | — |
| Debian 12 | xen | 4.2.2-1 | — |
| Debian 7 | xen | 4.1.4-3+deb7u2 | DSA-3006-1 |
Advisories 1
- DSA-3006-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- 55082 third-party-advisory
- GLSA-201309-24 vendor-advisory
- [oss-security] 20130603 Xen Security Advisory 52 (CVE-2013-2076) - Information leak on XSAVE/XRSTOR capable AMD CPUs mailing-list
- SUSE-SU-2014:0446 vendor-advisory
- DSA-3006 vendor-advisory