Cyber Resilience

CVE-2025-3891

High

Published: 29 April 2025

Published
29 April 2025
Modified
28 July 2025
KEV Added
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Patch
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CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0101 77.6th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-3891 is a high-severity Uncaught Exception (CWE-248) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 22.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

The vulnerability CVE-2025-3891 affects the mod_auth_openidc module for Apache httpd. It stems from improper handling of an empty POST request when the OIDCPreservePost directive is enabled, causing the server to crash consistently and resulting in a denial of service that impacts availability. The issue carries a CVSS 3.1 base score of 7.5 and is associated with CWE-248.

A remote unauthenticated attacker can exploit the flaw over the network by sending a specially crafted empty POST request to a vulnerable server with the directive enabled, achieving disruption of service without any authentication or user interaction required.

Red Hat has published multiple advisories (RHSA-2025:10002 through RHSA-2025:10007) that address the issue through updated packages for affected products.

The associated EPSS score remains low, with a current value of 0.0101 and a peak of 0.0133.

EU & UK References

Vulnerability details

A flaw was found in the mod_auth_openidc module for Apache httpd. This flaw allows a remote, unauthenticated attacker to trigger a denial of service by sending an empty POST request when the OIDCPreservePost directive is enabled. The server crashes consistently,…

more

affecting availability.

CWE(s)
CWE-248NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
Why these techniques?

CVE-2025-3891 enables denial of service by crashing the Apache httpd server with mod_auth_openidc via an empty POST request when OIDCPreservePost is enabled, facilitating endpoint DoS through application exploitation.

MITRE ATLAS TechniquesAI

MITRE ATLAS techniques

AML.T0048: External Harms

Affected Assets

apache
http server
all versions
redhat
enterprise linux
7.0, 8.0, 9.0
debian
debian linux
11.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-24 Fail in Known State
addresses: CWE-248

Prevents abrupt termination from uncaught exceptions by requiring a defined, preserved-state failure mode.

SI-17 Fail-safe Procedures
addresses: CWE-248

Requires pre-defined safe responses for uncaught exceptions so they do not result in undefined or insecure program termination.

References