CVE-2013-4345
Description
From CVE.org
Off-by-one error in the get_prng_bytes function in crypto/ansi_cprng.c in the Linux kernel through 3.11.4 makes it easier for context-dependent attackers to defeat cryptographic protection mechanisms via multiple requests for small amounts of data, leading to improper management of the state of the consumed data.
Statement
This issue affects the versions of Linux kernel as shipped with Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2. Future kernel updates for Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2 may address this issue.
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 | 2.6 | 5.8 | N/A |
| Attack Vector | Local | Network | N/A |
| Access Complexity | High | Medium | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | Partial | Partial | N/A |
| Integrity Impact | Partial | Partial | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: AV:L/AC:H/Au:N/C:P/I:P/A:N
NVD: AV:N/AC:M/Au:N/C:P/I:P/A:N
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Instability
This weakness will generally lead to undefined behavior and therefore crashes. In the case of overflows involving loop index variables, the likelihood of infinite loops is also high.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the wrap around results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows which can be used to execute arbitrary code. This is usually outside the scope of a program's implicit security policy.
Acknowledgements
Red Hat would like to thank Stephan Mueller for reporting this issue.
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