CVE-2019-11779 : Exploit Details and Defense Strategies

Eclipse Mosquitto 1.5.0 to 1.6.5 inclusive is susceptible to a stack overflow vulnerability when a malicious MQTT client sends a SUBSCRIBE packet with a topic containing a large number of '/' characters.

Understanding CVE-2019-11779

This CVE involves a stack overflow issue in Eclipse Mosquitto versions 1.5.0 to 1.6.5, triggered by a specific type of MQTT packet.

What is CVE-2019-11779?

A stack overflow can occur in Eclipse Mosquitto 1.5.0 to 1.6.5 when a malicious MQTT client sends a SUBSCRIBE packet with a topic containing approximately 65400 or more '/' characters.

The Impact of CVE-2019-11779

Attackers can exploit this vulnerability to cause a denial of service (DoS) condition by crashing the Mosquitto broker.
This issue can lead to service disruption and potentially impact the availability of MQTT communication.

Technical Details of CVE-2019-11779

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The vulnerability in Eclipse Mosquitto versions 1.5.0 to 1.6.5 arises from a stack overflow triggered by a specific type of MQTT packet.

Affected Systems and Versions

Product: Eclipse Mosquitto
Vendor: The Eclipse Foundation
Versions Affected: 1.5.0 to 1.6.5 inclusive

Exploitation Mechanism

Exploitation involves sending a SUBSCRIBE packet with a topic containing a large number of '/' characters.

Mitigation and Prevention

Protecting systems from CVE-2019-11779 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply the vendor-provided security updates promptly.
Monitor network traffic for any suspicious activity targeting MQTT communication.
Implement proper input validation to prevent malformed MQTT packets.

Long-Term Security Practices

Regularly update and patch the Eclipse Mosquitto software to mitigate known vulnerabilities.
Conduct security assessments and audits to identify and address potential weaknesses in MQTT implementations.

Patching and Updates

Refer to the vendor advisories and security updates provided by Eclipse Foundation and other relevant sources to patch the vulnerability.