CPANSA-Plack-Middleware-Session-2025-40923: Plack-Middleware-Session vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2025-07-16T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2025-07-16T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | 7.3 | Severity | |
| Original language | Language | en | |
| Also referred to | |||
Vulnerability 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.
Vulnerabilities
CVE-2025-40923
Vulnerability DescriptionPlack-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.
| Weakness | CWE-338 : Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) |
|---|
Product status
Known affected
| Product | Score | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Plack-Middleware-Session less than 0.35 |
|
Fixed
- Plack-Middleware-Session greater than or equal 0.35
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Plack-Middleware-Session-2025-40923 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2025/cpansa-plack-middleware-session-2025-40923.json - https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch external
https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch - https://github.com/plack/Plack-Middleware-Session/pull/52 external
https://github.com/plack/Plack-Middleware-Session/pull/52 - https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22 external
https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22 - https://security.metacpan.org/docs/guides/random-data-for-security.html external
https://security.metacpan.org/docs/guides/random-data-for-security.html - CVE-2025-40923 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2025-40923
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Wed Jul 16 00:00:00 2025 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/