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CVE-2025-40932NVD status: Analyzed

Apache::SessionX: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

CVE-2025-40932 is a high-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in Apache::SessionX from Grichter, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Apache::SessionX versions: 2.01 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Apache::SessionX you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
GRICHTERApache::SessionX2.01 and earlierNot stated
GrichterApache2.01 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N. Scored by CISA (ADP).

Official description

Apache::SessionX versions through 2.01 for Perl create insecure session id. Apache::SessionX generates session ids insecurely. The default session id generator in Apache::SessionX::Generate::MD5 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.

How developers prevent this class of flaw

  • Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.

More Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities (CWE-338)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities

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