CVE-2020-12656
Description
A flaw was found in the implementation of the Linux kernel’s GSS mechanism registration functionality. During this period, memory allocation was not freed when the module was unloaded, leading to a memory leak. This flaw allows an attacker with the ability to repeat loads and unloads, to cause the system to run out of free memory and crash eventually.
Statement
This issue is rated as having Low impact because of the preconditions needed to trigger the issue (privileges requried to mount/unmount a module). The issue is also being disputed with MITRE (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12656) as being a non-issue because of the privileges required.
Mitigation
There is no mitigation to this flaw other than to prevent the loading of the affected kernel module.
A user with permission to load a kernel module would also likely have permission to overcome any blacklisting on the system.
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 v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.4 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | High | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Most memory leaks result in general product reliability problems, but if an attacker can intentionally trigger a memory leak, the attacker might be able to launch a denial of service attack (by crashing or hanging the program) or take advantage of other unexpected program behavior resulting from a low memory condition.
Other
Technical Impact: Reduce Performance
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