CVE-2025-40931
Chorny Apache::session::generate::md5 vulnerability
- Published5 Mar 2026
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NAffected products
Remediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
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
- https://www.openwall.com/lists/oss-security/2019/06/15/1
- http://www.openwall.com/lists/oss-security/2026/03/05/3
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2025-40931 being actively exploited?
CVE-2025-40931 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.59%.
How severe is CVE-2025-40931?
CVE-2025-40931 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.59% probability of exploitation.
Which products are affected by CVE-2025-40931?
Affected products include Chorny Apache::session::generate::md5.
How do I fix CVE-2025-40931?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2025-40931 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.