Back

CRITICAL KEV Used in ransomware campaigns

Apache ActiveMQ, Apache ActiveMQ Legacy OpenWire Module: Unbounded deserialization causes ActiveMQ to be vulnerable to a remote code execution (RCE) attack

Published Oct 27, 2023 ·Due Nov 23, 2023

Description

The Java OpenWire protocol marshaller is vulnerable to Remote Code Execution. This vulnerability may allow a remote attacker with network access to either a Java-based OpenWire broker or client to run arbitrary shell commands by manipulating serialized class types in the OpenWire protocol to cause either the client or the broker (respectively) to instantiate any class on the classpath.

Users are recommended to upgrade both brokers and clients to version 5.15.16, 5.16.7, 5.17.6, or 5.18.3 which fixes this issue.

Affected products

Remediation

Red Hat statement

If the openwire protocol IS NOT in use, system operators can disable the OpenWire protocol which removes most risk of this vulnerability being exploited. If OpenWire IS being used, see the Mitigations section for potential options to reduce your attack surface. * How to determine if an AMQ 7 system is affected: Check in the broker.xml configuration file. Notice the presence of **OPENWIRE** in the following snippet which indicates a vulnerable configuration. ~~~ <acceptor name="artemis">tcp://localhost:####?tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576;protocols=CORE,AMQP,STOMP,HORNETQ,MQTT,**OPENWIRE**;useEpoll=true;amqpCredits=1000;amqpLowCredits=300;anycastPrefix=jms.queue.;multicastPrefix=jms.topic.</acceptor> ~~~ * How to determine if an AMQ 7 for OpenShift system is affected: Get the `ActivemqArtemis` CR yaml and review the acceptor protocol and see if the following entry is present: `(default, all, Openwire)` which indicates the system is vulnerable. * How to determine if a Fuse 6 system is affected: By default Fuse 6 includes and enables ActiveMQ Broker. So unless this has been manually disabled, every Fuse 6 system is affected by this vulnerability. * How to determine if a Fuse 7 system is affected: Fuse 7 itself is not vulnerable. By default it ships the vulnerable activemq-client jar, however it does not instantiate an ActiveMQ broker. If this feature (connect to an external ActiveMQ Broker) were manually configured, it would make it vulnerable. * How to determine if a Fuse Online system is affected: Syndesis, an Integration Platform As A Service part of Fuse Online which runs on top of Openshift, does not use activemq code. Also, it doesn't instantiate a broker with Openwire protocol enabled, which makes it not vulnerable to this CVE.

Red Hat mitigation

In affected systems, it may be possible to mitigate some of the risks from this vulnerability. However this mitigation cannot eliminate all risks; the only complete resolution is to apply software updates. On systems where the broker is exposed to the public network, use firewall rules to restrict the transport ports and enable SSL to protect this "Transport".

References (26)

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED
Assigner apache
Published Oct 27, 2023
Updated Nov 3, 2025
Reserved Oct 24, 2023

CISA Vulnrichment

Updated Feb 4, 2025

NVD

Status Analyzed
Modified Jun 17, 2026

Red Hat

Severity Critical
Public date Oct 27, 2023
Bugzilla 2246645

ENISA EUVD

Assigner apache
Published Oct 27, 2023
Updated Nov 3, 2025
Exploited since Nov 2, 2023