CVE-2025-40931
Apache::Session::Generate::MD5 versions through 1.94 for Perl create insecure session id
- State
- Published
- Severity
- 9.1 Critical
- Published
- Mar 5, 2026
- Updated
- Apr 21, 2026
- Reserved
- Apr 16, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | CISA-ADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
Apache::Session::Generate::MD5CHORNY |
|
References
- https://metacpan.org/dist/Apache-Session/source/lib/Apache/Session/Generate/MD5.pm#L27
- https://security.metacpan.org/docs/guides/random-data-for-security.htmltechnical-description
- https://github.com/chorny/Apache-Session/issues/4issue-tracking
- https://rt.cpan.org/Ticket/Display.html?id=173631issue-tracking
- https://www.openwall.com/lists/oss-security/2019/06/15/1mailing-list
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=930659issue-tracking
- https://salsa.debian.org/perl-team/modules/packages/libapache-session-perl/-/commit/bdabd71c2f91b18526e31a9dc52b4c17b3d246b7#898a4b8b00022df1b8689910b67707f3e738d180patch
- https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/1633issue-tracking
- https://metacpan.org/pod/Apache::Session::Generate::Random
- http://www.openwall.com/lists/oss-security/2026/03/05/3
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