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

Critical severity GitHub Reviewed Published Oct 22, 2018 to the GitHub Advisory Database • Updated Jan 9, 2023

Package

maven com.typesafe.akka:akka-actor_2.11 (Maven)

Affected versions

>= 2.5.0, < 2.5.16

Patched versions

2.5.16
maven com.typesafe.akka:akka-actor_2.12 (Maven)
>= 2.5.0, < 2.5.16
2.5.16

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.

References

Published to the GitHub Advisory Database Oct 22, 2018
Reviewed Jun 16, 2020
Last updated Jan 9, 2023

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS score

0.168%
(55th percentile)

Weaknesses

CVE ID

CVE-2018-16115

GHSA ID

GHSA-mr95-9rr4-668f

Source code

No known source code
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