CVE-2015-7513
Description
A divide-by-zero flaw was discovered in the Linux kernel built with KVM virtualization support(CONFIG_KVM). The flaw occurs in the KVM module's Programmable Interval Timer(PIT) emulation, when PIT counters for channel 1 or 2 are set to zero(0) and a privileged user inside the guest attempts to read these counters. A privileged guest user with access to PIT I/O ports could exploit this issue to crash the host kernel (denial of service).
Statement
This issue does not affect the versions of the kernel package as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise MRG 2.
This issue affects the versions of Linux kernel as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.
This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/
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 | 4.3 | 4.9 | N/A |
| Attack Vector | Adjacent Network | Local | N/A |
| Access Complexity | High | Low | 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:A/AC:H/Au:S/C:N/I:N/A:C
NVD: AV:L/AC:L/Au:N/C:N/I:N/A:C
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
A Divide by Zero results in a crash.
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