CVE-2025-40931
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering.
- Exploit odds
- 0.6% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.6% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.6% · EPSS, next 30 days
- Weakness
- CWE-338
- Record status
- Modified
Affected
- Chorny apache\ ≤ 1.94
Attack profile CVSS 3.1 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-40931.md and follow it. Check whether this project is affected by CVE-2025-40931. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
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