CVE-2025-14104 is a vulnerability identified in the util-linux package of Red Hat Enterprise Linux 10, specifically within the setpwnam() function responsible for processing usernames. The flaw manifests as a heap buffer over-read when the system processes usernames exactly 256 bytes in length. This vulnerability affects SUID (Set User ID) login utilities that write to the password database, which are critical components in user authentication and management. The over-read occurs because the function does not properly validate or limit the length of the username input, leading to reading beyond the allocated heap buffer. This can cause memory corruption, potentially resulting in a denial of service (DoS) by crashing the affected utilities or the system processes that rely on them. The CVSS 3.1 base score is 6.1, indicating a medium severity level. The vector string (AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H) shows that the attack requires local access with low complexity, privileges are required but no user interaction is needed, and the impact is limited to confidentiality (partial information disclosure) and availability (high impact due to DoS), with no integrity impact. No known exploits are currently reported in the wild, suggesting limited active exploitation at this time. The vulnerability is significant because it affects core system utilities involved in authentication, which are often SUID and run with elevated privileges, increasing the risk of system instability or denial of service if exploited. Given the nature of the flaw, exploitation is limited to local attackers with some privileges, such as authenticated users or processes running with limited rights. The vulnerability does not appear to allow privilege escalation or remote code execution directly. However, the denial of service impact can disrupt critical services and user authentication workflows.

For European organizations, the primary impact of CVE-2025-14104 is the potential for denial of service on systems running Red Hat Enterprise Linux 10, particularly those that rely on SUID login utilities for authentication and user management. This could lead to temporary loss of access to critical systems or services, affecting business continuity and operational stability. Confidentiality impact is limited but may include partial leakage of memory contents due to the heap over-read, which could expose sensitive information in some scenarios. The requirement for local privileges limits the attack surface to internal threat actors or compromised accounts. Organizations operating critical infrastructure, data centers, or cloud environments using RHEL 10 are at higher risk, especially if they have automated processes or scripts that depend on these utilities. The absence of known exploits in the wild reduces immediate risk, but the medium severity rating and the nature of the vulnerability warrant prompt attention. Disruption of authentication services can have cascading effects on compliance, user productivity, and incident response capabilities. The impact is more pronounced in environments with high user turnover or where usernames of unusual length might be processed, potentially triggering the vulnerability.

To mitigate CVE-2025-14104, European organizations should prioritize applying official patches from Red Hat as soon as they become available. In the interim, organizations can audit and restrict username lengths to below 256 bytes to prevent triggering the over-read condition. Review and harden access controls to limit local user privileges, reducing the number of accounts capable of exploiting this vulnerability. Implement monitoring for unusual crashes or denial of service symptoms in login utilities and related authentication services. Consider deploying application whitelisting and integrity monitoring on critical system binaries to detect unauthorized modifications or crashes. Conduct thorough testing of authentication workflows with edge-case usernames to identify potential triggers. Additionally, organizations should review their incident response plans to quickly address any denial of service incidents related to this vulnerability. For environments with high security requirements, consider isolating critical authentication services or using alternative authentication mechanisms until patches are applied. Finally, maintain up-to-date inventory of systems running Red Hat Enterprise Linux 10 to ensure comprehensive coverage of mitigation efforts.