CVE-2020-13985 in Contiki
Summary
by MITRE • 12/12/2020
An issue was discovered in Contiki through 3.0. A memory corruption vulnerability exists in the uIP TCP/IP stack component when handling RPL extension headers of IPv6 network packets in rpl_remove_header in net/rpl/rpl-ext-header.c.
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Analysis
by VulDB Data Team • 12/16/2020
The vulnerability identified as CVE-2020-13985 represents a critical memory corruption flaw within the Contiki operating system version 3.0 and earlier, specifically affecting the uIP TCP/IP stack component. This issue manifests when processing RPL extension headers within IPv6 network packets, creating a potential avenue for attackers to exploit memory handling mechanisms within the network stack. The vulnerability resides in the rpl_remove_header function located in the net/rpl/rpl-ext-header.c file, which processes routing information in the RPL (Routing Protocol for Low-Power and Lossy Networks) protocol implementation. The flaw demonstrates particular significance in constrained environments where Contiki is commonly deployed, such as IoT devices and embedded systems that rely on efficient network communication protocols.
The technical root cause of this vulnerability stems from improper handling of RPL extension headers during packet processing, specifically within the memory management routines of the uIP stack. When the rpl_remove_header function processes IPv6 packets containing RPL extension headers, it fails to properly validate or sanitize the header structure before performing memory operations. This deficiency creates opportunities for buffer overflows or memory corruption conditions that can be triggered through crafted malicious packets. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, addressing out-of-bounds read errors, both of which are commonly associated with improper memory handling in network protocol implementations. The flaw essentially allows attackers to manipulate memory structures through malformed packet headers, potentially leading to arbitrary code execution or system instability.
The operational impact of CVE-2020-13985 extends beyond simple network disruption, as it can compromise the integrity and availability of embedded systems running Contiki. Devices utilizing this network stack for RPL-based routing, such as sensor networks, smart meters, and industrial IoT deployments, face potential compromise when exposed to malicious network traffic. Attackers could exploit this vulnerability to execute arbitrary code on affected devices, potentially gaining full control over networked systems and enabling lateral movement within secured environments. The vulnerability particularly affects systems implementing the RPL protocol for low-power and lossy networks, which are prevalent in industrial control systems, smart grid infrastructure, and wireless sensor networks where reliability and security are paramount. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for execution through command and scripting interpreter, and T1499.004 for network denial of service, potentially enabling broader attack chains within affected networks.
Mitigation strategies for CVE-2020-13985 require immediate attention from system administrators and developers working with Contiki-based deployments. The primary recommendation involves upgrading to Contiki version 3.1 or later, where the memory corruption issue has been addressed through improved header validation and memory management routines. Organizations should also implement network segmentation and monitoring to detect anomalous packet patterns that might indicate exploitation attempts. Additional defensive measures include configuring firewalls to filter malformed IPv6 packets containing RPL headers, implementing network intrusion detection systems to identify suspicious traffic patterns, and conducting regular security assessments of embedded network infrastructure. The vulnerability highlights the importance of proper input validation in network protocol implementations and demonstrates how seemingly minor flaws in memory handling can create significant security risks in embedded systems. Organizations should also consider implementing network access controls and regular patch management procedures to ensure all Contiki-based systems remain protected against similar vulnerabilities.