CVE-2025-40923
Description
A random session id generation flaw has been discovered in Plack-Middleware-Session. By default, session ids are generated by a SHA-1 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. Predicable session ids could allow an attacker to gain access to systems.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
If a PRNG is used for authentication and authorization, such as a session ID or a seed for generating a cryptographic key, then an attacker may be able to easily guess the ID or cryptographic key and gain access to restricted functionality.
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