CVE-2023-50926 in Contiki-NG
Summary
by MITRE • 02/14/2024
Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. An out-of-bounds read can be caused by an incoming DIO message when using the RPL-Lite implementation in the Contiki-NG operating system. More specifically, the prefix information of the DIO message contains a field that specifies the length of an IPv6 address prefix. The value of this field is not validated, which means that an attacker can set a value that is longer than the maximum prefix length. Subsequently, a memcmp function call that compares different prefixes can be called with a length argument that surpasses the boundary of the array allocated for the prefix, causing an out-of-bounds read. The problem has been patched in the "develop" branch of Contiki-NG, and is expected to be included in the next release. Users are advised to update as soon as they are able to or to manually apply the changes in Contiki-NG pull request #2721.
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Analysis
by VulDB Data Team • 01/07/2025
The vulnerability CVE-2023-50926 affects Contiki-NG, a widely-used open-source operating system designed for next-generation internet of things devices. This security flaw resides within the RPL-Lite implementation, which is responsible for routing protocols in resource-constrained IoT environments. The issue manifests when the system processes incoming DIO (Directed Information Object) messages, which are fundamental components of the Routing Protocol for Low-Power and Lossy Networks. The vulnerability represents a critical out-of-bounds read condition that can be exploited by remote attackers to potentially disrupt system operations or extract sensitive information from memory.
The technical root cause stems from inadequate validation of the prefix length field within DIO messages. Specifically, the implementation fails to validate that the prefix length specified in the DIO message does not exceed the maximum allowable IPv6 prefix length. This validation gap allows attackers to craft malicious DIO messages with artificially inflated prefix length values that surpass the allocated memory boundaries. When the system processes these malformed messages, a memcmp function is invoked with an incorrect length parameter that exceeds the allocated array bounds, resulting in memory access violations. This type of vulnerability falls under CWE-129, which addresses insufficient validation of length parameters, and represents a classic example of buffer over-read conditions that can lead to information disclosure and system instability.
The operational impact of this vulnerability extends beyond simple denial-of-service scenarios, as it can potentially enable attackers to extract confidential data from memory locations adjacent to the affected buffer. In IoT environments where Contiki-NG operates, such attacks could compromise the integrity of routing information, potentially allowing attackers to redirect traffic or establish man-in-the-middle positions within the network. The vulnerability is particularly concerning given that Contiki-NG is deployed in critical infrastructure applications where reliability and security are paramount. Attackers exploiting this issue could leverage the out-of-bounds read to gain insights into the system's memory layout, potentially facilitating more sophisticated attacks or bypassing security mechanisms. The attack surface is broad as any device running Contiki-NG with RPL-Lite enabled could be targeted, making this a significant concern for IoT network administrators and security teams.
Mitigation strategies for CVE-2023-50926 should prioritize immediate software updates to the latest stable release of Contiki-NG, which includes the patch implemented in pull request #2721. Organizations should also implement network monitoring to detect anomalous DIO message patterns that might indicate exploitation attempts. The fix involves adding proper validation of the prefix length field before any memory operations are performed, ensuring that the length parameter passed to memory functions remains within acceptable bounds. Security teams should also consider implementing network segmentation and access controls to limit exposure, while maintaining awareness of the ATT&CK framework's relevant techniques such as T1059 for command and control communications and T1566 for credential access through network infiltration. Additionally, regular security assessments of IoT deployments using Contiki-NG should be conducted to identify and remediate similar vulnerabilities that may exist in the broader codebase, particularly focusing on memory safety and input validation controls that align with industry best practices for embedded systems security.