Low

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in Ratpack

  • Disclosed: 14.05.2019
  • Updated: 11.10.2026 11:21

Ratpack versions before 1.6.1 generate a session ID using a cryptographically weak PRNG in the JDK's ThreadLocalRandom. This means that if an attacker can determine a small window for the server start time and obtain a session ID value, they can theoretically determine the sequence of session IDs.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) io.ratpack:ratpack-groovy < 1.6.1 1.6.1
Java / Kotlin (Maven) io.ratpack:ratpack-java < 1.6.1 1.6.1
Java / Kotlin (Maven) io.ratpack:ratpack-session < 1.6.1 1.6.1

References

CVSS score 3.7/10
CVSS vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE)
CWE-338
Platform
Java / Kotlin (Maven)
Package
io.ratpack:ratpack-groovy, io.ratpack:ratpack-java, io.ratpack:ratpack-session
Disclosed
14.05.2019
Updated
11.10.2026 11:21

Sources and licenses

OSV / GitHub Advisory Database - GHSA-54mg-vgrp-mwx9 - CC BY 4.0

Vulnerability history: io.ratpack:ratpack-session

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
3
First → latest
05.2019 07.2021
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Medium 2
  • Low 1

Disclosures per year

  1. 2019: 1
  2. 2020: 0
  3. 2021: 2
  4. 2022: 0
  5. 2023: 0
  6. 2024: 0
  7. 2025: 0
  8. 2026: 0
  1. Medium · 6.5 CVE-2021-29481 < 1.9.0 1.9.0
  2. Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in Ratpack this entry
    Low · 3.7 CVE-2019-11808 < 1.6.1 1.6.1

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