CVE-2018-12679 in CoAPthon3
Summary
by MITRE
The Serialize.deserialize() method in CoAPthon3 1.0 and 1.0.1 mishandles certain exceptions, leading to a denial of service in applications that use this library (e.g., the standard CoAP server, CoAP client, example collect CoAP server and client) when they receive crafted CoAP messages.
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Analysis
by VulDB Data Team • 08/21/2023
The vulnerability identified as CVE-2018-12679 resides within the CoAPthon3 library version 1.0 and 1.0.1, specifically targeting the Serialize.deserialize() method implementation. This flaw represents a critical security weakness that can be exploited to induce denial of service conditions in CoAP-based applications. The vulnerability manifests when applications utilizing this library process specially crafted CoAP messages that trigger improper exception handling within the deserialization routine. The affected components include standard CoAP servers, CoAP clients, and example implementations such as the collect CoAP server and client, making the impact widespread across CoAP ecosystem implementations.
The technical root cause of this vulnerability stems from inadequate exception management within the deserialization process of CoAP messages. When the Serialize.deserialize() method encounters malformed or crafted CoAP packets, it fails to properly handle the resulting exceptions, leading to abrupt application termination or resource exhaustion. This behavior creates a predictable denial of service condition where an attacker can send specifically crafted CoAP messages that cause the target application to crash or become unresponsive. The flaw operates at the protocol parsing layer, where the library's inability to gracefully handle malformed input leads to system instability. According to CWE classification, this vulnerability aligns with CWE-400, which covers "Uncontrolled Resource Consumption," and CWE-248, addressing "Exception Handling Errors." The vulnerability demonstrates characteristics of improper exception handling that can be leveraged to disrupt service availability.
The operational impact of CVE-2018-12679 extends beyond simple application crashes, as it can be exploited to create sustained denial of service conditions in IoT environments where CoAP servers and clients are prevalent. In smart home systems, industrial IoT deployments, and sensor networks that rely on CoAP for communication, this vulnerability can effectively disable critical infrastructure components. The attack vector requires minimal sophistication, as an attacker only needs to send malicious CoAP messages to trigger the vulnerable code path. This makes the vulnerability particularly dangerous in environments where automated systems or services depend on continuous CoAP communication. The vulnerability affects both server and client implementations, meaning that a single malicious message could potentially compromise multiple system components. Organizations implementing CoAP-based solutions must consider this vulnerability as a potential threat to their operational continuity, especially in mission-critical applications where service availability is paramount.
Mitigation strategies for CVE-2018-12679 should focus on immediate library updates to versions that address the exception handling flaws. The most effective solution involves upgrading to CoAPthon3 versions that contain proper exception handling mechanisms within the Serialize.deserialize() method. Organizations should also implement network-level protections such as CoAP message filtering, rate limiting, and input validation at network boundaries to prevent malicious packets from reaching vulnerable applications. Additionally, application-level defensive measures including proper error handling, timeout mechanisms, and resource monitoring can help detect and recover from exploitation attempts. Security teams should conduct comprehensive vulnerability assessments of all CoAP-based systems and implement monitoring to detect potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1499.004, "Endpoint Denial of Service," highlighting the importance of protecting against resource exhaustion attacks. System administrators should also consider implementing intrusion detection systems that can identify suspicious CoAP traffic patterns associated with this specific vulnerability. Regular security updates and patch management processes should be established to prevent similar issues from arising in future library versions.