CVE-2017-2892 in Mongoose
Summary
by MITRE
An exploitable arbitrary memory read vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6.8. A specially crafted MQTT packet can cause an arbitrary out-of-bounds memory read and write potentially resulting in information disclosure, denial of service and remote code execution. An attacker needs to send a specially crafted MQTT packet over the network to trigger this vulnerability.
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Analysis
by VulDB Data Team • 01/06/2023
The CVE-2017-2892 vulnerability represents a critical arbitrary memory read flaw within the MQTT packet parsing component of Cesanta Mongoose version 6.8. This vulnerability resides in the network protocol handling mechanism that processes MQTT messages, making it particularly dangerous in IoT and embedded systems environments where such protocols are commonly deployed. The flaw stems from inadequate bounds checking during packet parsing operations, allowing malicious actors to craft specific MQTT packets that can trigger memory access violations.
The technical implementation of this vulnerability involves a classic buffer over-read condition where the Mongoose library fails to properly validate the length and structure of incoming MQTT packets before attempting to parse them. When processing a malformed packet, the parser accesses memory locations beyond the allocated buffer boundaries, potentially reading sensitive data from adjacent memory regions or causing memory corruption that leads to system instability. This type of vulnerability is classified under CWE-125 as an out-of-bounds read, and can be leveraged as a stepping stone for more sophisticated attacks. The vulnerability operates at the application layer of the network stack, specifically targeting the MQTT protocol implementation within the embedded web server framework.
The operational impact of CVE-2017-2892 extends beyond simple information disclosure to encompass potential system compromise and service disruption. An attacker exploiting this vulnerability can gain access to sensitive memory contents including authentication credentials, system configuration data, or application state information that could be used to further compromise the affected system. The arbitrary memory read capability also enables attackers to perform memory layout reconnaissance, which is valuable for advanced exploitation techniques. In addition to information disclosure, the vulnerability can cause denial of service conditions by corrupting memory structures or triggering application crashes through memory access violations. The potential for remote code execution exists when the memory corruption leads to control flow hijacking, making this vulnerability particularly attractive to threat actors targeting IoT devices and embedded systems.
Mitigation strategies for CVE-2017-2892 should focus on immediate patching of the Cesanta Mongoose library to version 6.9 or later, which contains the necessary bounds checking fixes. Network segmentation and firewall rules can help limit exposure by restricting MQTT traffic to trusted networks and reducing the attack surface. Implementing network monitoring and intrusion detection systems can help identify suspicious MQTT packet patterns that may indicate exploitation attempts. Organizations should also consider disabling MQTT functionality if it is not essential to their operations, and implementing proper input validation at multiple network layers. From an ATT&CK framework perspective, this vulnerability maps to techniques involving protocol manipulation and memory corruption, and should be addressed through defensive measures that include network traffic analysis, application whitelisting, and regular security assessments of embedded systems. The vulnerability underscores the importance of proper input validation and memory safety practices in embedded systems development, particularly in IoT environments where such devices often lack traditional security controls.