Catalyst::Plugin::Session before version 0.44 for Perl generates session ids insecurely

published 2025-07-17 15 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-21775

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

Catalyst::Plugin::Session before version 0.44 for Perl generates session ids insecurely.

The session id is generated from a (usually SHA-1) hash of a simple counter, the epoch time, the built-in rand function, the PID and the current Catalyst context. This information is of low entropy. 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.

Patch / fix

fixed in 1 distros 1 links 2

HAARG Catalyst::Plugin::Session 0.44

libcatalyst-plugin-session-perl Debian 14 0.44-1

debian advisories DEBIAN-CVE-2025-40924

github.com/perl-catalyst/Catalyst-Plugin-Session@c0e2b4a commit
github.com/perl-catalyst/Catalyst-Plugin-Session#5 pull request

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-40924 updated 2026-06-28 cvss 5.9

catalyst-plugin-session: Catalyst::Plugin::Session generates session ids insecurely

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 15 mo ago (2025-07-17)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

HAARG Catalyst::Plugin::Session

Classification

Weakness

CWE-340 Generation of Predictable Numbers or Identifiers
CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

Sources

CVE List CVE-2025-40924
NVD CVE-2025-40924

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary