CVE-2018-16115: 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 Remot...

Description

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.

Metrics

EPSS Probability

1.19%

63.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-338

Affected Software

Vendor	Product	Versions
Lightbend	Akka	>= 2.5.0, < 2.5.16

References

https://doc.akka.io/docs/akka/current/security/2018-08-29-aes-rng.htmlVendor Advisory
https://doc.akka.io/docs/akka/current/security/2018-08-29-aes-rng.htmlVendor Advisory

Timeline

Published: Aug 29, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-16115?

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.

How severe is CVE-2018-16115?

Severity scoring for CVE-2018-16115 is pending analysis. The EPSS model estimates a 1.19% probability of exploitation in the next 30 days.

How do I fix CVE-2018-16115?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.