Vulnerability in Chorny Apache\
CVE-2025-40931
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Chorny Apache\ — versions \
- Chorny Apache::session::generate::md5 — versions 0
- Chorny Apache\:\:session\:\:generate\:\:md5
Weakness classification (CWE)
References
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (Product)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (technical-description, Mailing List, Third Party Advisory)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (issue-tracking, Issue Tracking)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (issue-tracking, Third Party Advisory)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (mailing-list)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (issue-tracking)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (patch)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e (issue-tracking)
- 9b29abf9-4ab0-4765-b253-1875cd9b441e
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2025-40931?
- CVE-2025-40931 is a critical-severity vulnerability in Chorny Apache\, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 9.1/10. Published 2026-03-05.
- How severe is CVE-2025-40931?
- Critical severity. CVSS v3 base score is 9.1 out of 10.