CVE-2021-45939 : Exploit Details and Defense Strategies

wolfSSL wolfMQTT 1.9 has a heap-based buffer overflow vulnerability in MqttClient_DecodePacket.

Understanding CVE-2021-45939

What is CVE-2021-45939?

wolfSSL wolfMQTT 1.9 is prone to a heap-based buffer overflow in MqttClient_DecodePacket, triggered from MqttClient_WaitType and MqttClient_Subscribe.

The Impact of CVE-2021-45939

The vulnerability could allow a remote attacker to execute arbitrary code or cause a denial of service (DoS) condition on the affected system.

Technical Details of CVE-2021-45939

Vulnerability Description

The vulnerability exists in the MqttClient_DecodePacket function of wolfSSL wolfMQTT 1.9, leading to a heap-based buffer overflow.

Affected Systems and Versions

Product: wolfSSL wolfMQTT 1.9
Version: Not applicable

Exploitation Mechanism

The vulnerability can be exploited by a remote attacker sending malicious MQTT packets, leading to the overflow in the decoding function.

Mitigation and Prevention

Immediate Steps to Take

Apply vendor-supplied patches or updates to address the vulnerability.
Monitor for any suspicious network activity.
Restrict network access to affected systems.

Long-Term Security Practices

Regularly update software and firmware to the latest versions.
Conduct security assessments and penetration testing on network-connected systems.

Patching and Updates

Refer to the vendor's security advisory for specific patching instructions and timelines.