Protocol‑Compliant DoS Attacks Undermine C‑V2X Safety Applications

Global: Protocol‑Compliant DoS Attacks Undermine C‑V2X Safety Applications

A recent study demonstrates that protocol‑compliant denial‑of‑service attacks can severely impair safety functions in connected vehicles, reducing the effectiveness of Forward Collision Warning (FCW) systems. The research, conducted on a real‑world testbed using commercially available on‑board units, shows that attacks adhering to 3GPP and SAE J2735 specifications can still cause near‑total communication failure.

Background and Standards

Cellular Vehicle‑to‑Everything (C‑V2X) technology is designed to provide low‑latency, reliable communications for safety‑critical applications. Deployments follow strict protocol compliance with the 3rd Generation Partnership Project (3GPP) and the Society of Automotive Engineers (SAE) J2735 standards to ensure interoperability across manufacturers.

UDP Flooding Attack

The study evaluated a UDP flooding attack that transmits valid messages over standard PC5 sidelinks at abnormally high rates. Results indicate that the packet delivery ratio drops by up to 87% and latency exceeds 400 ms, dramatically degrading FCW performance while remaining within protocol rules such as IEEE 1609.

Oversized BSM Attack

In a separate scenario, attackers sent oversized Basic Safety Messages (BSMs) that overload receiver processing resources. The oversized payloads delay or completely suppress FCW alerts, demonstrating that transport‑ and application‑layer vulnerabilities can be exploited without violating any formal specifications.

Combined Attack Impact

When UDP flooding and oversized BSM attacks are executed simultaneously, the testbed experiences near‑total communication failure, preventing FCW warnings from being generated at all. This combined effect highlights the compounded risk of multiple protocol‑compliant vectors operating together.

Safety Implications

Findings reveal that adherence to existing C‑V2X standards does not guarantee safe or reliable operation of safety applications. The ability to degrade or disable FCW alerts raises concerns for regulators, manufacturers, and end‑users who rely on these systems for collision avoidance.

Recommendations and Future Research

The authors suggest that additional detection mechanisms and resilience strategies be explored to mitigate protocol‑compliant DoS threats. Further research is needed to assess the effectiveness of such countermeasures in real‑world deployments.

This report is based on information from arXiv, licensed under Academic Preprint / Open Access. Based on the abstract of the research paper. Full text available via ArXiv.