CVE-2013-1992
Description
From CVE.org
Multiple integer overflows in X.org libdmx 1.1.2 and earlier allow X servers to trigger allocation of insufficient memory and a buffer overflow via vectors related to the (1) DMXGetScreenAttributes, (2) DMXGetWindowAttributes, and (3) DMXGetInputAttributes functions.
Statement
Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
This flaw only affects X clients that connect to malicious X servers. Generally speaking, these will be untrusted/unknown X servers only, as trusted remote X servers should be connected to via SSH (which provides end-point verification and authentication), or the local X server. Because this flaw requires that the X server be changed (recompiled to deviate from a standard X server) in order to impact the X client, it requires root privileges on the X server to effect the change. If this is a system where the X client and server are on the same (local) host, and an attacker is able to replace the X server binary, then they already have root privileges and no trust boundary is crossed. With remote X servers, using SSH with strict host-key checking will prevent the X client from connecting to the X server without intervention, as the user will be alerted to host-key changes.
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 | 4.3 | 6.8 | N/A |
| Attack Vector | Adjacent Network | 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 | Partial | Partial | N/A |
Vector
Red Hat: AV:A/AC:H/Au:N/C:P/I:P/A:P
NVD: AV:N/AC:M/Au:N/C:P/I:P/A:P
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.
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 overflow/wraparound 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 the product's implicit security policy.
Availability,Other
Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.
Access Control
Technical Impact: Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.
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