CVE-2016-3159
Description
From CVE.org
The fpu_fxrstor function in arch/x86/i387.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.
Statement
This issue does not affect the Xen hypervisor packages as shipped with Red Hat Enterprise Linux 5.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.8 | 1.7 | N/A |
| Attack Vector | Adjacent Network | Local | N/A |
| Access Complexity | Medium | Low | N/A |
| Authentication | Single | Single | N/A |
| Confidentiality Impact | Partial | Partial | N/A |
| Integrity Impact | Partial | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: AV:A/AC:M/Au:S/C:P/I:P/A:N
NVD: AV:L/AC:L/Au:S/C:P/I:N/A:N
Acknowledgements
Red Hat would like to thank the Xen project for reporting this issue.
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