CVE-2011-2212

Description

From CVE.org

Buffer overflow in the virtio subsystem in qemu-kvm 0.14.0 and earlier allows privileged guest users to cause a denial of service (guest crash) or gain privileges via a crafted indirect descriptor related to "virtqueue in and out requests."

Statement

This issue only affects Red Hat Enterprise Linux 6. The version of the qemu/kvm as shipped with Red Hat Enterprise Linux 5 is not affected because it does not provide support for indirect descriptors.

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 HatNVDcve.org
Base Score7.47.4N/A
Attack VectorAdjacent NetworkAdjacent NetworkN/A
Access ComplexityMediumMediumN/A
AuthenticationSingleSingleN/A
Confidentiality ImpactCompleteCompleteN/A
Integrity ImpactCompleteCompleteN/A
Availability ImpactCompleteCompleteN/A

Vector

Red Hat: AV:A/AC:M/Au:S/C:C/I:C/A:C

NVD: AV:A/AC:M/Au:S/C:C/I:C/A:C

Understanding the Weakness (CWE)

Integrity,Confidentiality,Availability

Technical Impact: Execute Unauthorized Code or Commands; Modify Memory

If the memory accessible by the attacker can be effectively controlled, it may be possible to execute arbitrary code, as with a standard buffer overflow. If the attacker can overwrite a pointer's worth of memory (usually 32 or 64 bits), they can alter the intended control flow by redirecting a function pointer to their own malicious code. Even when the attacker can only modify a single byte arbitrary code execution can be possible. Sometimes this is because the same problem can be exploited repeatedly to the same effect. Other times it is because the attacker can overwrite security-critical application-specific data -- such as a flag indicating whether the user is an administrator.

Availability,Confidentiality

Technical Impact: Read Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.

Confidentiality

Technical Impact: Read Memory

In the case of an out-of-bounds read, the attacker may have access to sensitive information. If the sensitive information contains system details, such as the current buffer's position in memory, this knowledge can be used to craft further attacks, possibly with more severe consequences.

Acknowledgements

Red Hat would like to thank Nelson Elhage for reporting this issue.

Frequently Asked Questions

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