CVE-2021-3894
Description
A vulnerability was found in the Linux kernel. This flaw allows an unprivileged local user to panic the system, resulting in a denial of service by calling setsockopt(2) with specially crafted arguments. The highest threat from this vulnerability is to system availability.
Statement
This flaw was found to be a duplicate of CVE-2022-0322. Please see https://access.redhat.com/security/cve/CVE-2022-0322 for information about affected products and security errata.
Mitigation
As the SCTP module will be auto-loaded when required, its use can be disabled by preventing the module from loading with the following instructions:
# echo "install sctp /bin/true" >> /etc/modprobe.d/disable-sctp.conf
The system will need to be restarted if the SCTP modules are loaded. In most circumstances, the CIFS kernel modules will be unable to be unloaded while any network interfaces are active and the protocol is in use.
If the system requires this module to work correctly, this mitigation may not be suitable.
If you need further assistance, see the KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
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 | 0 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:N
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an attacker can trigger the allocation of the limited resources, but the number or size of the resources is not controlled, then the most common result is denial of service. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment, i.e., the product may slow down, crash due to unhandled errors, or lock out legitimate users. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
Frequently Asked Questions
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