by Kastro
Paper/Archive/CVE-2025-40926

CVE-2025-40926

KAZEBURO Plack::Middleware::Session::Simple — Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely

EPSS 0.5%CVSS 9.8
critical.is priorityof 100
38
CVSS 9.8 (ADP)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 43.1.431 × 208.6No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Plack::Middleware::Session::Simple versions before 0.05 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. Predictable session ids could allow an attacker to gain access to systems. Plack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.

Affected

ProductAffectedFixed inSource
Plack::Middleware::Session::Simple< 0.050.05CNA

Scores by source

CISA ADP9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refmetacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43refgithub.com/kazeburo/Plack-Middleware-Session-Simple/pull/4patchgithub.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patchadvisorycve.org/CVERecord?id=CVE-2025-40923writeupsecurity.metacpan.org/docs/guides/random-data-for-security.htmlrefmetacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes