CVE-2015-8701
Description
An off-by-one vulnerability was discovered in the QEMU emulator built with Rocker-switch emulation support. The flaw occurred when processing transmit(tx) descriptors in the 'tx_consume' routine, if a descriptor had more than the allowed fragments (ROCKER_TX_FRAGS_MAX=16).
Statement
This issue does not affect the versions of the kvm and xen packages as shipped with Red Hat Enterprise Linux 5.
This issue does not affect 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.
This issue does not affect the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 7.
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.
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 | 2.9 | 2.1 | 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 | Partial | None | N/A |
| Availability Impact | Partial | Partial | N/A |
Vector
Red Hat: AV:A/AC:H/Au:S/C:N/I:P/A:P
NVD: AV:L/AC:L/Au:N/C:N/I:N/A:P
Understanding the Weakness (CWE)
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
Acknowledgements
Red Hat would like to thank Qinghao Tang (Qihoo 360) for reporting this issue.
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