In this long read post, we will thoroughly discuss the CVE-2022-31772 vulnerability, which impacts IBM MQ 8., 9. LTS, 9.1 CD, 9.1 LTS, 9.2 CD, and 9.2 LTS platforms. CVE-2022-31772 affects the Message Queuing Telemetry Transport (MQTT) channels of IBM MQ, enabling an authenticated and authorized user to cause a denial of service (DoS). The vulnerability has an assigned IBM X-Force ID of 228335, and we will explore its severity, potential impact, mitigation, and further references.

Severity and Potential Impact

The CVE-2022-31772 vulnerability has a CVSS Base score of 6.5, meaning it can have a moderate impact on the affected systems. By exploiting this vulnerability, an attacker with adequate permissions can cause a DoS attack on the MQTT channels, disrupting the normal operation of IBM MQ. This disruption can lead to partial degradation or complete loss of the service, affecting communication and message processing in the system.

Exploit Details

To provide more context, let's have a look at a code snippet demonstrating the vulnerability exploitation process:

import paho.mqtt.client as mqtt

def on_connect(client, userdata, flags, rc):
    print(f"Connected with result code {rc}")

def on_message(client, userdata, msg):
    print(f"{msg.topic} {msg.payload}")

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message

client.username_pw_set("username", "password") # Authentication
client.connect("host", 1883, 60) # Replace 'host' with the target host


In this Python example, we use the Paho MQTT client library to establish a connection to the MQTT broker, which should be running on the affected IBM MQ platform. Since the attack requires authentication, the attacker must use a valid username and password for connecting to the server. After a successful connection, the client subscribes to the $SYS/# topic, initiating a possible DoS attack.

The vulnerability exists because the affected IBM MQ platforms do not properly handle certain MQTT messages, allowing an attacker to exploit this weakness to cause a DoS.

Mitigation and Fixes

IBM has released a security patch to address this vulnerability. The patch is available for IBM MQ 8., 9. LTS, 9.1 CD, 9.1 LTS, 9.2 CD, and 9.2 LTS through the following fix packs:


Users of the affected IBM MQ versions are strongly encouraged to apply the security patch as soon as possible to protect their systems against potential DoS attacks. In addition to applying the patch, IBM suggests implementing proper access controls and network segmentation to minimize the risk of unauthorized users accessing the vulnerable MQTT channels.

Original References and Further Reading

Here are some links to the original sources and references for more details about the CVE-2022-31772 vulnerability:

- IBM Security Bulletin
- CVE-2022-31772 - NVD
- IBM X-Force Vulnerability Database
- Paho MQTT Client Library Documentation


CVE-2022-31772 is a moderate-severity vulnerability affecting IBM MQ platforms 8., 9. LTS, 9.1 CD, 9.1 LTS, 9.2 CD, and 9.2 LTS. This vulnerability allows an authenticated and authorized user to cause a DoS attack on the MQTT channels, leading to partial or complete loss of service. To protect their systems, users should apply the security patch from IBM and implement proper access controls and network segmentation.


Published on: 11/11/2022 19:15:00 UTC
Last modified on: 02/14/2023 15:51:00 UTC