Arbitrary Code Execution Affecting com.typesafe.akka:akka-actor package, versions [,2.4.17) [2.5-M1,2.5-M2)

com.typesafe.akka:akka-actor is message-driven application builder on the JVM.

Affected versions of the package are vulnerable to Arbitrary Code Execution. An attacker that can connect to an ActorSystem exposed via Akka Remote over TCP can gain remote code execution capabilities in the context of the JVM process that runs the ActorSystem if:

• JavaSerializer is enabled (default in Akka 2.4.x)

• and TLS is disabled or TLS is enabled with akka.remote.netty.ssl.security.require-mutual-authentication = false (which is still the default in Akka 2.4.x)
• or if TLS is enabled with mutual authentication and the authentication keys of a host that is allowed to connect have been compromised, an attacker gained access to a valid certificate (e.g. by compromising a node with certificates issued by the same internal PKI tree to get access of the certificate)

• regardless of whether untrusted mode is enabled or not

Java deserialization is known to be vulnerable to attacks when attacker can provide arbitrary types.

• Github Vulnerability Advisory
• Java Deserialization Vulnerability
• NVD