CVE-2024-32018 in RIOT-OS
Summary
by MITRE • 05/01/2024
RIOT is a real-time multi-threading operating system that supports a range of devices that are typically 8-bit, 16-bit and 32-bit microcontrollers. Most codebases define assertion macros which compile to a no-op on non-debug builds. If assertions are the only line of defense against untrusted input, the software may be exposed to attacks that leverage the lack of proper input checks. In detail, in the `nimble_scanlist_update()` function below, `len` is checked in an assertion and subsequently used in a call to `memcpy()`. If an attacker is able to provide a larger `len` value while assertions are compiled-out, they can write past the end of the fixed-length `e->ad` buffer. If the unchecked input above is attacker-controlled and crosses a security boundary, the impact of the buffer overflow vulnerability could range from denial of service to arbitrary code execution. This issue has not yet been patched. Users are advised to add manual `len` checking.
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Analysis
by VulDB Data Team • 09/04/2025
The vulnerability described in CVE-2024-32018 affects RIOT OS, a real-time multi-threading operating system designed for embedded devices typically utilizing 8-bit, 16-bit, and 32-bit microcontrollers. This operating system serves critical infrastructure applications where security and reliability are paramount, making such vulnerabilities particularly concerning. The issue stems from improper input validation mechanisms within the nimble_scanlist_update() function, which processes Bluetooth advertising data in wireless communication modules. The vulnerability represents a classic buffer overflow scenario where defensive programming practices are insufficiently enforced in production builds.
The technical flaw manifests in the function's handling of the len parameter through assertion-based validation rather than explicit input sanitization. Assertions are typically disabled in release builds, creating a security gap where attacker-controlled input can bypass validation checks. When assertions are compiled-out, the len parameter is directly used in a memcpy() operation without proper bounds checking against the fixed-length e->ad buffer. This creates a predictable buffer overflow condition where an attacker can manipulate the len value to exceed the buffer boundaries, potentially writing arbitrary data beyond the intended memory allocation. The vulnerability is classified as a buffer overflow under CWE-121 and represents a memory safety issue that can be exploited across multiple attack vectors.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enable arbitrary code execution within the embedded system's memory space. When attacker-controlled input crosses security boundaries such as network interfaces or wireless communication protocols, the buffer overflow can be leveraged to overwrite critical program data, function pointers, or return addresses. This aligns with ATT&CK technique T1059 for command and control execution and T1203 for exploitation for privilege escalation. The vulnerability affects the integrity and availability of embedded systems that rely on RIOT OS for wireless connectivity, potentially compromising entire IoT ecosystems where these devices serve as communication endpoints or gateway nodes.
Mitigation strategies for CVE-2024-32018 require immediate implementation of explicit input validation before buffer operations. System administrators and developers should add manual bounds checking for the len parameter in the nimble_scanlist_update() function, ensuring that input values are validated against the maximum buffer size before any memory operations occur. The recommended approach involves implementing proper input sanitization that functions consistently regardless of compilation flags or debug settings. Additionally, defensive programming practices should be enforced throughout the codebase, particularly in functions handling external data inputs. Given the nature of embedded systems, memory protection mechanisms such as stack canaries or memory segmentation should be considered as additional layers of defense. The vulnerability highlights the importance of not relying solely on assertions for security boundaries and emphasizes the need for robust input validation in all security-critical code paths.