MIYAGAWA Plack::Middleware::Session up to 0.34 on Perl rand generation of predictable numbers or identifiers

Summaryinfo

A vulnerability, which was classified as problematic, was found in MIYAGAWA Plack::Middleware::Session up to 0.34 on Perl. This issue affects the function rand. The manipulation results in generation of predictable numbers or identifiers. This vulnerability is cataloged as CVE-2025-40923. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in MIYAGAWA Plack::Middleware::Session up to 0.34 on Perl. Affected is the function rand. The manipulation with an unknown input leads to a generation of predictable numbers or identifiers vulnerability. CWE is classifying the issue as CWE-340. The product uses a scheme that generates numbers or identifiers that are more predictable than required. This is going to have an impact on confidentiality. CVE summarizes:

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.

The advisory is shared for download at metacpan.org. This vulnerability is traded as CVE-2025-40923 since 04/16/2025. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1600.001.

Upgrading to version 0.35 eliminates this vulnerability. Applying the patch 1fbfbb355e34e7f4b3906f66cf958cedadd2b9be is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-21693). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Middleware

Vendor

• MIYAGAWA

Name

• Plack::Middleware::Session

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34

License

• open-source

CPE 2.3info

• 🔒
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CPE 2.2info

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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