CVE-2017-2895 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 SUBSCRIBE packet can cause an arbitrary out-of-bounds memory read potentially resulting in information disclosure and denial of service. An attacker needs to send a specially crafted MQTT packet over the network to trigger this vulnerability.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/05/2019
The vulnerability identified as CVE-2017-2895 represents a critical security flaw in Cesanta Mongoose 6.8's MQTT packet parsing implementation that exposes systems to arbitrary memory read attacks. This issue manifests within the MQTT protocol handling subsystem where the software fails to properly validate incoming SUBSCRIBE packets, creating a pathway for malicious actors to access memory regions beyond the intended buffer boundaries. The vulnerability operates at the network protocol level, specifically targeting the message queue management functionality that processes MQTT subscriptions, making it particularly dangerous for IoT devices and embedded systems that rely on Mongoose for network communications.
The technical exploitation of this vulnerability stems from inadequate bounds checking during MQTT packet parsing operations, which falls under the CWE-129 weakness category for improper input validation. When a specially crafted SUBSCRIBE packet is transmitted to a vulnerable Mongoose instance, the parser attempts to read memory locations that are not properly validated against the actual packet boundaries. This out-of-bounds memory access can result in the disclosure of sensitive information from adjacent memory segments, potentially exposing system credentials, internal data structures, or cryptographic keys. The vulnerability is classified as an information disclosure issue under the ATT&CK framework's T1005 technique, as it allows adversaries to extract confidential data from memory.
The operational impact of this vulnerability extends beyond simple information disclosure, as the arbitrary memory read can also lead to denial of service conditions when the parser encounters corrupted memory references or triggers system crashes. Attackers can leverage this vulnerability to systematically extract memory contents through repeated packet submissions, potentially enabling more sophisticated attacks such as heap spraying or further exploitation techniques. The network-based nature of the attack means that any device running vulnerable Mongoose software and exposed to untrusted network traffic becomes a potential target, particularly affecting IoT deployments, industrial control systems, and embedded network appliances that utilize MQTT for device communication and data exchange.
Mitigation strategies for CVE-2017-2895 require immediate software updates to the latest stable versions of Cesanta Mongoose that address the memory parsing flaws. Organizations should implement network segmentation and access controls to limit exposure to untrusted MQTT traffic, while also deploying intrusion detection systems capable of identifying malformed MQTT packets. The vulnerability demonstrates the importance of proper input validation in network protocol implementations, emphasizing the need for defensive programming practices such as bounds checking and memory safety mechanisms. Additionally, security monitoring should include detection of unusual memory access patterns and unauthorized information disclosure attempts that may indicate exploitation attempts against similar vulnerabilities in other network services.