CVE-2014-3640
Description
A NULL pointer dereference flaw was found in the way QEMU handled UDP packets with a source port and address of 0 when QEMU's user networking was in use. A local guest user could use this flaw to crash the guest.
Statement
This issue did not affect the kvm package as shipped with Red Hat Enterprise Linux 5.
Red Hat Product Security has rated this issue as having Low security impact. Future qemu-kvm updates for Red Hat Enterprise Linux 6 and 7 may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
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).
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.4 | 2.1 | N/A |
| Attack Vector | Local | Local | N/A |
| Access Complexity | Medium | Low | N/A |
| Authentication | Single | None | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Complete | Partial | N/A |
Vector
Red Hat: AV:L/AC:M/Au:S/C:N/I:N/A:C
NVD: AV:L/AC:L/Au:N/C:N/I:N/A:P
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.
Acknowledgements
Red Hat would like to thank Stephane Duverger (Airbus) and Xavier Mehrenberger for reporting this issue.
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