CVE-2016-3158
Description
The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2016-3158
Vendor advisory: cve@mitre.org — http://xenbits.xen.org/xsa/xsa172.patch
Vendor advisory: cve@mitre.org — http://xenbits.xen.org/xsa/xsa172-4.3.patch
Vendor advisory: cve@mitre.org — http://xenbits.xen.org/xsa/advisory-172.html
Vendor advisory: cve@mitre.org — http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| fedora | 22 | affected | |
| fedora | 23 | affected | |
| debian | bookworm | fixed | 4.8.0~rc3-1 |
| debian | bullseye | fixed | 4.8.0~rc3-1 |
| debian | forky | fixed | 4.8.0~rc3-1 |
| debian | sid | fixed | 4.8.0~rc3-1 |
| debian | trixie | fixed | 4.8.0~rc3-1 |
References
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181699.html
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181729.html
- http://support.citrix.com/article/CTX209443
- http://www.debian.org/security/2016/dsa-3554
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
- http://www.securityfocus.com/bid/85714
- http://www.securitytracker.com/id/1035435
- http://xenbits.xen.org/xsa/advisory-172.html
- http://xenbits.xen.org/xsa/xsa172-4.3.patch
- http://xenbits.xen.org/xsa/xsa172.patch
- https://security-tracker.debian.org/tracker/CVE-2016-3158
CWEs
CWE-200 CWE-284
Verify integrity in audit chain (admin only). AS-IS.