CVE-2022-36053 is a medium-severity vulnerability classified as an out-of-bounds read (CWE-125) found in Contiki-NG, an open-source operating system designed for next-generation Internet of Things (IoT) devices. The vulnerability resides in the low-power IPv6 network stack, specifically within the buffer module located at os/net/ipv6/uipbuf.c. The function uipbuf_get_next_header is responsible for processing IPv6 extension headers in incoming network packets. It does so by casting pointers to a uip_ext_hdr structure at various offsets where extension headers are expected. However, due to insufficient bounds checking, this casting can result in the structure extending beyond the actual end of the packet buffer. Consequently, when a carefully crafted IPv6 packet with malicious extension headers is received, the system may read memory outside the intended packet buffer boundaries. This out-of-bounds read can lead to information disclosure or potentially cause undefined behavior such as system crashes or memory corruption. The vulnerability affects all Contiki-NG versions prior to 4.8, where a patch addressing this issue has been incorporated. There are no known exploits in the wild at the time of this analysis, and exploitation does not require authentication but does require the attacker to send specially crafted IPv6 packets to the vulnerable device. User interaction is not necessary beyond network communication. The vulnerability impacts confidentiality and potentially availability due to memory safety violations, but does not directly enable code execution or privilege escalation.

For European organizations deploying IoT devices running Contiki-NG, particularly in critical infrastructure sectors such as smart city deployments, industrial automation, healthcare, and energy management, this vulnerability poses a risk of information leakage and potential device instability. Attackers could exploit this flaw to read sensitive memory contents from IoT devices, which might include cryptographic keys, configuration data, or other sensitive information. This could facilitate further attacks such as device impersonation or network infiltration. Additionally, the out-of-bounds read could cause device crashes or reboots, leading to denial of service conditions in environments where IoT devices play a critical role in operational continuity. Given the increasing adoption of IoT technologies in Europe and the reliance on IPv6 networking in modern deployments, the vulnerability could affect a broad range of devices, especially those in constrained environments where Contiki-NG is favored for its low-power and lightweight characteristics. However, the absence of known exploits and the medium severity rating suggest that immediate widespread impact is limited but should not be underestimated in sensitive deployments.

European organizations should prioritize updating all Contiki-NG-based IoT devices to version 4.8 or later, where the vulnerability has been patched. For devices that cannot be immediately updated, network-level mitigations should be implemented, including deploying IPv6 packet inspection and filtering to detect and block malformed IPv6 extension headers that could exploit this vulnerability. Network segmentation and isolation of IoT devices can limit exposure to potentially malicious traffic. Additionally, organizations should monitor network traffic for unusual IPv6 packets with suspicious extension headers and implement anomaly detection systems tailored for IoT network behavior. Vendors and integrators should verify firmware versions and ensure secure update mechanisms are in place to facilitate timely patch deployment. Finally, security assessments and penetration testing focusing on IPv6 stack robustness in IoT deployments can help identify residual risks.