CVE-2017-10915
Description
From CVE.org
The shadow-paging feature in Xen through 4.8.x mismanages page references and consequently introduces a race condition, which allows guest OS users to obtain Xen privileges, aka XSA-219.
Mitigation
Where the HVM guest is explicitly configured to use shadow paging (eg
via the `hap=0' xl domain configuration file parameter), changing to
HAP (eg by setting `hap=1') will avoid exposing the vulnerability to
those guests. HAP is the default (in upstream Xen), where the
hardware supports it; so this mitigation is only applicable if HAP has
been disabled by configuration.
(This mitigation is not applicable to PV guests.)
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 v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.5 | 9 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Acknowledgements
Red Hat would like to thank the Xen project for reporting this issue. Upstream acknowledges Andrew Cooper (Citrix) as the original reporter.
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