CVE-2025-40931CRITICAL 9.1EPSS p43.3%
CVE-2025-40931CVE-2025-40931
Description
Apache::Session::Generate::MD5 versions through 1.94 for Perl create insecure session id.
Apache::Session::Generate::MD5 generates session ids insecurely. The default session id generator returns a MD5 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.
Note that the libapache-session-perl package in some Debian-based Linux distributions may be patched to use Crypt::URandom.
Scoring
| CVSS 3.1 | 9.1 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| EPSS | 0.58% probability of exploitation · percentile 43.3% · 2026-06-19T12:03:05Z |
| Published | 2026-03-05 |
| Last modified | 2026-04-12 |
Underlying weaknesses· 2
References
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=930659
- https://github.com/chorny/Apache-Session/issues/4
- https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/1633
- https://metacpan.org/dist/Apache-Session/source/lib/Apache/Session/Generate/MD5.pm#L27
- https://metacpan.org/pod/Apache::Session::Generate::Random
- https://rt.cpan.org/Ticket/Display.html?id=173631
- https://salsa.debian.org/perl-team/modules/packages/libapache-session-perl/-/commit/bdabd71c2f91b18526e31a9dc52b4c17b3d246b7#898a4b8b00022df1b8689910b67707f3e738d180
- https://security.metacpan.org/docs/guides/random-data-for-security.html
2
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)cwe-338 | 0% | live |
| Weakness | Generation of Predictable Numbers or Identifierscwe-340 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.