PT-2025-29824 · Miyagawa · Plack::Middleware::Session

Published 2025-07-16 · Updated 2025-07-16 · CVE-2025-40923

NVD

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.

Weakness Enumeration

CWE-338

CWE-340

Related Identifiers

CVE-2025-40923

Affected Products

Plack::Middleware::Session

References · 6

• https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2025-40923 · Security Note
• https://github.com/plack/Plack-Middleware-Session/pull/52 · Note
• https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22 · Note
• https://twitter.com/CVEnew/status/1945482456905433157 · Twitter Post
• https://security.metacpan.org/docs/guides/random-data-for-security.html · Note