CVE-2015-8340
Description
A malicious guest administrator may be able to deny service by crashing the host or causing a deadlock by timing memory handling events between the guest and the host.
Statement
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 6, 7, MRG-2 and realtime kernels.
At this time, there is no plans to fix this issue, if you feel that this issue is affecting your deployment and have an EUS subscription, please contact support to have this issue correctly prioritized
Mitigation
The vulnerability can be avoided if the guest kernel is controlled by the host rather than guest administrator, provided that further steps are taken to prevent the guest administrator from loading code into the kernel (e.g. by disabling loadable modules etc) or from using other mechanisms which allow them to run code at kernel privilege. In Xen HVM, controlling the guest's kernel would involve locking down the bootloader.
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 | 6.2 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.3 | 4.7 | N/A |
| Attack Vector | Network | Local | N/A |
| Access Complexity | Medium | Medium | N/A |
| Authentication | Single | None | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Complete | Complete | N/A |
Vector
Red Hat: AV:N/AC:M/Au:S/C:N/I:N/A:C
NVD: AV:L/AC:M/Au:N/C:N/I:N/A:C
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Inconsistent locking discipline can lead to deadlock.
Acknowledgements
Red Hat would like to thank the Xen project for reporting this issue. Upstream acknowledges Jan Beulich (SUSE) and Julien Grall (Citrix) as the original reporters.
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