Critical

Cryptographically Weak Pseudo-Random Number Generator (PRNG) in akka-actor

  • Disclosed: 22.10.2018
  • Updated: 11.10.2026 11:20

Lightbend Akka 2.5.x before 2.5.16 allows message disclosure and modification because of an RNG error. A random number generator is used in Akka Remoting for TLS (both classic and Artery Remoting). Akka allows configuration of custom random number generators. For historical reasons, Akka included the AES128CounterSecureRNG and AES256CounterSecureRNG random number generators. The implementations had a bug that caused the generated numbers to be repeated after only a few bytes. The custom RNG implementations were not configured by default but examples in the documentation showed (and therefore implicitly recommended) using the custom ones. This can be used by an attacker to compromise the communication if these random number generators are enabled in configuration. It would be possible to eavesdrop, replay, or modify the messages sent with Akka Remoting/Cluster.

Affected software

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PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) com.typesafe.akka:akka-actor_2.11 >= 2.5.0, < 2.5.16 2.5.16
Java / Kotlin (Maven) com.typesafe.akka:akka-actor_2.12 >= 2.5.0, < 2.5.16 2.5.16

References

CVSS score 9.1/10
CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE)
CWE-338
Platform
Java / Kotlin (Maven)
Package
com.typesafe.akka:akka-actor_2.11, com.typesafe.akka:akka-actor_2.12
Disclosed
22.10.2018
Updated
11.10.2026 11:20

Sources and licenses

OSV / GitHub Advisory Database - GHSA-mr95-9rr4-668f - CC BY 4.0

Vulnerability history: com.typesafe.akka:akka-actor_2.12

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.

This is the only known vulnerability of this package.

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