CVE-2015-3209
Description
A flaw was found in the way QEMU's AMD PCnet Ethernet emulation handled multi-TMD packets with a length above 4096 bytes. A privileged guest user in a guest with an AMD PCNet ethernet card enabled could potentially use this flaw to execute arbitrary code on the host with the privileges of the hosting QEMU process.
Statement
This issue does not affect the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 7 as they do not enable the pcnet backend driver.
This issue does not affect the Red Hat Enterprise Linux 7 based versions of the qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3.
This issue affects the versions of the kvm and xen packages as shipped with Red Hat Enterprise Linux 5, the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 6, and the Red Hat Enterprise Linux 6 based versions of qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3. Future updates for the respective releases may address this flaw.
Please note that AMD PCNet adapter has to be explicitly enabled per-guest as it is not enabled in default configuration and is not supported by Red Hat in Red Hat Enterprise Linux 6 (for a list of supported devices please consult https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Administration_Guide/sect-whitelist-device-options.html).
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 | 6.5 | 7.5 | N/A |
| Attack Vector | Adjacent Network | Network | N/A |
| Access Complexity | High | Low | N/A |
| Authentication | Single | None | N/A |
| Confidentiality Impact | Complete | Partial | N/A |
| Integrity Impact | Complete | Partial | N/A |
| Availability Impact | Complete | Partial | N/A |
Vector
Red Hat: AV:A/AC:H/Au:S/C:C/I:C/A:C
NVD: AV:N/AC:L/Au:N/C:P/I:P/A:P
Acknowledgements
Red Hat would like to thank Matt Tait (Google's Project Zero security team) for reporting this issue.
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