CVE-2015-5158
Description
A flaw has been discovered in the QEMU emulator built with SCSI-device emulation support. The emulator is vulnerable to a stack buffer overflow issue, which can occur while parsing a SCSI command descriptor block with an invalid operation code. A privileged(CAP_SYS_RAWIO) user inside a guest could use this flaw to crash the QEMU instance resulting in a denial-of-service (DoS) attack.
Statement
This issue does not affect the versions of 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 7.
This issue does not affect 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 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 | 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: 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 Donghai Zhu (Alibaba) for reporting this issue.
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