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.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2016-3158 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue does not affect the Xen hypervisor packages as shipped with Red Hat Enterprise Linux 5.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 3.8 |
|---|---|
| Base Metrics | AV:A/AC:M/Au:S/C:P/I:P/A:N |
| Access Vector | Adjacent Network |
| Access Complexity | Medium |
| Authentication | Single |
| Confidentiality Impact | Partial |
| Integrity Impact | Partial |
| Availability Impact | None |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 5 | xen | Will not fix |
Vulmon