CVE-2025-34450 is a stack-based buffer overflow vulnerability identified in the rtl_433 project maintained by merbanan. The vulnerability resides in the parse_rfraw() function within src/rfraw.c, where the software processes raw RF input data. Versions up to and including 25.02, prior to commit 25e47f8, do not properly validate the size of incoming RF data, allowing crafted or excessively large inputs to overflow a stack buffer. This overflow can corrupt memory, potentially causing the application to crash or behave unpredictably. While the primary impact is denial of service, under certain conditions—such as specific memory layouts and absence of exploit mitigations—an attacker might leverage this overflow for arbitrary code execution or privilege escalation. The vulnerability requires local access to the RF input stream, as indicated by the CVSS vector (Attack Vector: Local). No user interaction or privileges are required, but the attacker must supply malicious RF data. rtl_433 is widely used for decoding signals from various RF devices including weather stations, sensors, and remote controls, often in IoT and hobbyist environments. The vulnerability was published on December 18, 2025, with a CVSS 4.0 base score of 6.9, reflecting medium severity due to the local attack vector and lack of authentication requirements. No public exploits have been reported to date, but the potential for denial of service and further exploitation warrants attention.

For European organizations, the primary impact of CVE-2025-34450 is the risk of denial of service in systems relying on rtl_433 for RF signal decoding. This can disrupt monitoring, automation, or data collection processes that depend on RF devices, potentially affecting operational continuity. In industrial or critical infrastructure contexts where rtl_433 is integrated into sensor networks or environmental monitoring, such disruptions could have safety or compliance implications. Although the vulnerability requires local RF input manipulation, attackers with physical proximity or access to RF transmission paths could exploit it. The possibility of further exploitation beyond denial of service, while environment-dependent, raises concerns for confidentiality and integrity if attackers achieve code execution. European organizations with IoT deployments, smart building systems, or research labs using rtl_433 should assess exposure. The medium severity rating suggests moderate risk but highlights the need for timely mitigation to prevent service interruptions and potential escalation.

To mitigate CVE-2025-34450, organizations should first verify the version of rtl_433 in use and upgrade to a version including the fix beyond commit 25e47f8 once it is released. If an official patch is not yet available, consider applying source code fixes manually by reviewing the changes in the commit addressing the buffer overflow. Restrict the source of RF input data to trusted and controlled environments to reduce the risk of receiving crafted malicious signals. Employ RF signal filtering or validation mechanisms upstream to detect and block anomalous or excessively large inputs. Implement runtime protections such as stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) where possible to hinder exploitation attempts. Monitor rtl_433 application logs and system behavior for crashes or anomalies indicative of attempted exploitation. For critical deployments, consider isolating rtl_433 instances in sandboxed or containerized environments to limit the impact of potential crashes or code execution. Finally, maintain awareness of updates from the rtl_433 project and security advisories to promptly apply patches.