CVE-2025-15578 identifies a cryptographic weakness in the session ID generation mechanism of TEEJAY's Maypole Perl framework versions 2.10 through 2.13. The vulnerability arises from the use of a weak pseudo-random number generator (PRNG) seeded with predictable values: system time (which can be inferred from HTTP response headers), the built-in Perl rand() function, and the process ID (PID). These inputs provide insufficient entropy and are partially observable or guessable by attackers, enabling them to predict or brute-force session IDs. Since session IDs are critical for maintaining authenticated user sessions, their predictability can lead to session hijacking, allowing attackers to impersonate legitimate users, access sensitive data, or perform unauthorized actions. The vulnerability is categorized under CWE-338, indicating the use of a cryptographically weak PRNG. No CVSS score has been assigned yet, and no known exploits have been reported in the wild. However, the lack of secure randomness in session ID generation is a fundamental security flaw that undermines session confidentiality and integrity. The affected product, Maypole, is a Perl web application framework used in various web services, and versions 2.10 through 2.13 are impacted. No official patches or updates have been linked, suggesting that users must implement interim mitigations or await vendor fixes. The vulnerability's exploitation does not require user interaction but does require knowledge of the system time and PID, which can be inferred or guessed. This vulnerability highlights the importance of using cryptographically secure random number generators for session management in web applications.

For European organizations, this vulnerability poses a significant risk to web applications built on the Maypole framework, particularly those handling sensitive or personal data subject to GDPR. Successful exploitation can lead to session hijacking, resulting in unauthorized access to user accounts, data breaches, and potential regulatory penalties. The predictability of session IDs compromises confidentiality and integrity, potentially allowing attackers to escalate privileges or impersonate users. This can disrupt business operations, damage reputation, and lead to financial losses. Organizations in sectors such as finance, healthcare, government, and e-commerce, which often use Perl-based web applications, may be particularly vulnerable. The absence of known exploits provides a window for proactive mitigation, but the fundamental weakness in session ID generation demands urgent attention to prevent future attacks. Additionally, the vulnerability could be leveraged in targeted attacks against critical infrastructure or high-value targets within Europe, increasing the threat landscape.

European organizations should immediately assess their use of the Maypole framework and identify affected versions (2.10 through 2.13). Since no official patches are currently available, organizations should implement the following mitigations: 1) Replace the default session ID generation mechanism with a cryptographically secure PRNG, such as those provided by Perl modules like Crypt::URandom or Crypt::Random. 2) Increase session ID length and complexity to reduce predictability. 3) Implement additional session security controls, including session expiration, IP address binding, and multi-factor authentication to limit the impact of session hijacking. 4) Monitor web server logs and application behavior for unusual session activity or repeated failed session validation attempts. 5) Educate developers on secure coding practices related to randomness and session management. 6) Plan for upgrading to a future Maypole version that addresses this vulnerability once released. 7) Consider deploying web application firewalls (WAFs) with rules to detect and block suspicious session-related activities. These measures will help reduce the risk until a vendor patch is available.