CVE-2019-12067
Description
A NULL pointer dereference flaw was found in the QEMU emulator's IDE AHCI emulator. Exploitation of the flaw could occur while committing DMA buffer in ahci_commit_buf() if the command header 'ad->cur_cmd' was null. A privileged guest user could use this flaw to crash the QEMU process instance resulting in DoS. Reduced performance of the system is the highest threat to the system.
Statement
The qemu-kvm package versions as shipped with Red Hat Enterprise Linux 6 and 7 are not affected by this issue.
The qemu-kvm package version as shipped with Red Hat Enterprise Linux 8 is affected by this issue. Future qemu-kvm updates for Red Hat Enterprise Linux 8 may address this issue.
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 | 3.2 | 6.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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