CVE-2014-1895
Description
From CVE.org
Off-by-one error in the flask_security_avc_cachestats function in xsm/flask/flask_op.c in Xen 4.2.x and 4.3.x, when the maximum number of physical CPUs are in use, allows local users to cause a denial of service (host crash) or obtain sensitive information from hypervisor memory by leveraging a FLASK_AVC_CACHESTAT hypercall, which triggers a buffer over-read.
Statement
Not vulnerable.
This issue did not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5.
This issue did not affect Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG 2 as we did not have support for Xen hypervisor.
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 | 5 | 5.8 | N/A |
| Attack Vector | Adjacent Network | Adjacent Network | N/A |
| Access Complexity | High | Medium | N/A |
| Authentication | Single | Single | N/A |
| Confidentiality Impact | Partial | Partial | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Complete | Complete | N/A |
Vector
Red Hat: AV:A/AC:H/Au:S/C:P/I:N/A:C
NVD: AV:A/AC:M/Au:S/C:P/I:N/A:C
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability
This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.
Acknowledgements
Red Hat would like to thank Xen project for reporting this issue.
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