CVE-2025-40932 in Apache::SessionX
Summary
by MITRE • 02/27/2026
Apache::SessionX versions through 2.01 for Perl create insecure session id.
Apache::SessionX generates session ids insecurely. The default session id generator in Apache::SessionX::Generate::MD5 returns a MD5 hash seeded with the built-in rand() function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.
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Analysis
by VulDB Data Team • 03/02/2026
Apache::SessionX version 2.01 and earlier contains a critical cryptographic vulnerability in its session identifier generation mechanism that fundamentally compromises session security. This vulnerability stems from the insecure implementation of the MD5 hash generation process within the Apache::SessionX::Generate::MD5 module, which creates predictable session identifiers that can be easily guessed or reconstructed by malicious actors. The flaw manifests through the use of multiple predictable seeding factors including the system's built-in rand() function, epoch time values, and process identification numbers that are inherently limited in their entropy. The rand() function in Perl is explicitly designed for general-purpose random number generation and lacks the cryptographic security properties required for session identifier creation, making it susceptible to statistical analysis and prediction attacks.
The technical implementation of this vulnerability exposes systems to significant operational risks as attackers can reconstruct session identifiers by leveraging the predictable nature of the seeding parameters. The process identification number (PID) typically originates from a limited range of values, while epoch timestamps can be guessed or obtained through network reconnaissance techniques, particularly when the HTTP Date header is not properly obfuscated or when attackers can monitor session creation timing patterns. This vulnerability directly maps to CWE-330 Use of Insufficiently Random Values, which specifically addresses the use of weak random number generators in security-sensitive contexts. The combination of these factors creates a scenario where an attacker with minimal resources can potentially predict future session identifiers and gain unauthorized access to user sessions, effectively bypassing authentication mechanisms entirely.
The operational impact of this vulnerability extends beyond simple session hijacking to encompass broader system compromise and data breach risks. When attackers can predict session identifiers, they can not only access existing user sessions but may also be able to create new sessions with elevated privileges or impersonate legitimate users within the application. This vulnerability creates an attack surface that aligns with multiple ATT&CK techniques including T1566 Credential Access through Social Engineering and T1548 Valid Accounts for privilege escalation. The vulnerability's severity is compounded by the fact that it affects the fundamental session management layer of web applications, potentially allowing attackers to maintain persistent access to systems without detection. Organizations relying on Apache::SessionX for session management face significant risk of unauthorized access, data theft, and potential system compromise, particularly in environments where session identifiers are not properly secured or where attackers can observe session creation patterns.
Mitigation strategies should focus on immediate implementation of cryptographic-grade random number generators and comprehensive code review to replace the insecure MD5 generation mechanism. System administrators should upgrade to Apache::SessionX version 2.02 or later where this vulnerability has been addressed through the implementation of proper cryptographic random number generation. Organizations must also implement additional security controls including session identifier entropy monitoring, regular session validation checks, and proper HTTP header configuration to prevent leakage of timing information. The solution should incorporate industry-standard cryptographic libraries that provide sufficient entropy for session identifier generation, ensuring that session identifiers meet minimum security requirements for cryptographic strength. Security teams should also conduct thorough vulnerability assessments to identify systems still using vulnerable versions and implement monitoring for suspicious session access patterns that may indicate exploitation attempts.