CVE-2025-54656 is a vulnerability classified under CWE-117 (Improper Output Neutralization for Logs) found in Apache Struts Extras, specifically affecting versions prior to 2. The issue occurs when the LookupDispatchAction component logs untrusted input without proper sanitization or filtering. This improper handling allows specially crafted input to inject log entries that can masquerade as separate log lines, thereby corrupting the log structure. Such log injection can mislead automated log parsers or human analysts, potentially hiding malicious activity or causing confusion during incident investigations. The vulnerability does not directly compromise system confidentiality or availability but undermines the integrity and trustworthiness of log data, which is critical for security monitoring and forensic analysis. Notably, Apache Struts Extras is a retired project, and no official patches or updates will be provided to address this vulnerability. The CVSS score is 6.5 (medium severity), reflecting the ease of remote exploitation without authentication or user interaction, but limited impact scope. No known exploits are currently reported in the wild. Organizations still running this unsupported software face ongoing risk, especially if logs are relied upon for security operations. The recommended course of action is to migrate to supported frameworks or isolate and restrict access to affected instances to trusted users only.

For European organizations, the primary impact of CVE-2025-54656 lies in the degradation of log integrity and reliability. Since logs are essential for detecting, analyzing, and responding to security incidents, manipulated logs can delay or misdirect incident response efforts, increasing the risk of undetected breaches or prolonged compromise. This is particularly critical for sectors with stringent compliance requirements such as finance, healthcare, and critical infrastructure, where accurate logging is mandated. The vulnerability does not directly expose sensitive data or disrupt service availability, but the indirect effects on security monitoring can lead to increased risk exposure. Organizations using legacy Apache Struts Extras components in production environments may face challenges in maintaining compliance with EU regulations like GDPR and NIS Directive due to compromised audit trails. Additionally, attackers could leverage this vulnerability to cover tracks after exploiting other weaknesses, complicating forensic investigations. The lack of vendor support exacerbates the risk, as no patches will be forthcoming, forcing organizations to rely on compensating controls or migration strategies.

Given that Apache Struts Extras is a retired project with no forthcoming patches, the most effective mitigation is to migrate applications to supported and actively maintained frameworks that provide secure logging mechanisms. If immediate migration is not feasible, organizations should implement strict network segmentation and access controls to limit exposure of affected systems to trusted users only. Deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious input patterns targeting LookupDispatchAction may provide temporary protection. Additionally, enhancing log monitoring to detect anomalies in log structure or unexpected log entries can help identify exploitation attempts. Organizations should also conduct thorough audits of existing logs to identify potential manipulation and improve incident response readiness. Finally, updating internal security policies to prohibit use of unsupported software and enforce timely patching and upgrades will reduce future risk.