PT-2025-51894 · Riot-Os · Riot-Os

Nils-Bernsdorf

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Published

2025-12-17

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Updated

2026-01-22

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CVE-2025-66647

CVSS v3.1

9.8

Critical

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions RIOT versions prior to 2025.10
Description RIOT is an open-source microcontroller operating system designed for Internet of Things (IoT) devices and other embedded systems. A flaw exists in the IPv6 fragmentation reassembly implementation. Specifically, when copying the first fragment (offset=0) into the reassembly buffer, there is no size validation. An attacker can exploit this by sending a smaller fragment first, forcing the creation of a small reassembly buffer. Subsequently, overflowing this buffer can corrupt other packet buffers, potentially leading to memory corruption and remote code execution. To trigger this, the gnrc ipv6 ext frag module must be included, and the attacker needs to send arbitrary IPv6 packets to the target device.
Recommendations Update to RIOT version 2025.10 or later.

Exploit

Fix

RCE

Buffer Overflow

Weakness Enumeration

Related Identifiers

CVE-2025-66647
GHSA-WH3V-Q6VR-J79R

Affected Products

Riot-Os