CVE-2025-57784 identifies a timing attack vulnerability in the authentication mechanism of Hiawatha Web server version 11.7. The root cause is the use of the standard C library function strcmp to compare authentication credentials, which is not constant-time and leaks timing information based on how many characters match before a difference is found. This side channel allows a local attacker to perform an observable timing discrepancy attack (CWE-208) to gradually infer valid authentication tokens or passwords. By repeatedly measuring the time taken to process authentication attempts, the attacker can reconstruct the secret used by the Tomahawk authentication module, thereby gaining unauthorized access to the management client interface. The vulnerability requires local access to the server, as remote exploitation is not indicated. No public exploits have been reported yet, and no CVSS score has been assigned. The management client typically controls critical server configurations, so unauthorized access can lead to full compromise of the web server’s integrity and confidentiality. The absence of a patch link suggests that a fix may not yet be publicly available, increasing the urgency for defensive measures. This vulnerability highlights the importance of using constant-time comparison functions in security-sensitive code to prevent timing side channels.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of web server management interfaces. If exploited, attackers with local access could gain administrative control over the Hiawatha web server, potentially altering configurations, deploying malicious content, or disrupting services. This could lead to data breaches, service outages, and loss of trust. Organizations in sectors with stringent regulatory requirements such as finance, healthcare, and critical infrastructure could face compliance violations and reputational damage. The local access requirement limits the attack surface but does not eliminate risk, especially in environments where multiple users have server access or where attackers can gain footholds through other vulnerabilities. The lack of a patch increases exposure time. European entities relying on Hiawatha for web services must consider this vulnerability a high priority to avoid cascading impacts on their IT infrastructure and data protection obligations under GDPR.

To mitigate CVE-2025-57784, organizations should first verify if they are running Hiawatha Web server version 11.7 and restrict local access to trusted administrators only. Network segmentation and strict access controls can limit exposure to local attackers. Since no official patch is currently available, administrators should consider applying code-level mitigations such as replacing the unsafe strcmp function with a constant-time comparison function to eliminate timing discrepancies. Monitoring authentication logs for repeated failed attempts and unusual timing patterns can help detect exploitation attempts. Employing host-based intrusion detection systems (HIDS) to alert on suspicious local activity is advisable. Additionally, consider upgrading to newer versions of Hiawatha once patches are released. Regular security audits and penetration testing focused on local privilege escalation and side-channel attacks will further reduce risk.