Apache ActiveMQ contains a deserialization of untrusted data vulnerability that may allow a remote attacker with network access to a broker to run shell commands by manipulating serialized class types in the OpenWire protocol to cause the broker to instantiate any class on the classpath.

Apache ActiveMQ could allow a remote attacker to execute arbitrary code on the system, caused by an error in the Fileserver web application. By sending a specially crafted HTTP PUT request and an HTTP MOVE request, an attacker could exploit this vulnerability to create an arbitrary file and execute arbitrary code on the system.

Apache ActiveMQ contains an improper input validation vulnerability that allows for code injection.

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ.

During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected.

Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue.

Existing users may implement mutual TLS to mitigate the risk on affected brokers.