CVE-2025-40923
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-07-16

Last updated on: 2025-11-04

Assigner: CPANSec

Description
Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely. The default session id generator returns 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. 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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Meta Information
Published
2025-07-16
Last Modified
2025-11-04
Generated
2026-05-27
AI Q&A
2025-07-16
EPSS Evaluated
2026-05-25
NVD
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
plack plack-session *
plack plack-middleware-session *
crypt sysrandom *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-340 The product uses a scheme that generates numbers or identifiers that are more predictable than required.
CWE-338 The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in Plack-Middleware-Session versions before 0.35 for Perl, where session IDs are generated insecurely. The default session ID generator uses a SHA-1 hash seeded with the built-in rand function, the epoch time, and the process ID (PID). Since the PID comes from a small set of numbers and the epoch time can be guessed or leaked, and because the built-in rand function is not suitable for cryptographic purposes, the generated session IDs are predictable.


How can this vulnerability impact me? :

Because the session IDs are predictable, an attacker could potentially guess or reproduce valid session IDs, allowing them to gain unauthorized access to user sessions and systems that rely on these session IDs for authentication.


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0/70
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