CVE-2025-40109
Description
A flaw was found in the Linux kernel’s cryptographic random number generation (RNG) code where the set_ent routine, responsible for incorporating additional entropy, was not guaranteed to be present except in the deterministic random bit generator (DRBG) implementation. This could result in incomplete entropy mixing in non-DRBG RNG paths, weakening randomness used for cryptographic operations. Although exploitation requires local access and does not directly lead to privilege escalation, inadequate randomness can compromise cryptographic strength and potentially lead to system instability or weakened security guarantees
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | 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 | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
An attacker could guess the random numbers generated and could gain unauthorized access to a system if the random numbers are used for authentication and authorization.
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