Indirect prompt injection is a growing concern in AI technology. This happens when bots misinterpret input data as commands. Researchers have shown that self-driving cars and drones can be manipulated by illicit messages displayed on road signs. This new form of attack poses serious risks, such as self-driving cars ignoring pedestrians or drones following the wrong vehicles.
Academics from the University of California, Santa Cruz, and Johns Hopkins University conducted studies revealing how AI systems can be hijacked using visual prompts. In their tests, they demonstrated how simply changing the display of signs, from text to font style, can influence AI decisions. Using commands in multiple languages like English, Spanish, and even Spanglish proved successful in their experiments.
The team developed a method called CHAI, or “command hijacking against embodied AI,” to manipulate AI responses. They found that not only the wording of the commands mattered, but how they were visually presented—such as color and placement—also affected success rates. During virtual tests, they achieved an impressive 81.8% success rate in tricking self-driving cars.
The researchers experimented with scenarios involving both virtual and physical environments. They used two advanced AI models, GPT-4o and InternVL, to see how effectively they could be manipulated. In physical tests, they employed remote-controlled cars to assess how the AI responded to visual cues, finding that the GPT-4o model could be hijacked with a high success rate of 92.5% under certain conditions.
Beyond cars, the researchers also explored the implications for drones. In some cases, drones were tricked into misidentifying police vehicles, illustrating the critical need for robust safeguards in AI systems. As AI becomes increasingly integrated into everyday life, understanding these vulnerabilities is vital.
Expert opinions underline the urgency of addressing these issues. Dr. Alvaro Cardenas, a professor involved in the research, emphasizes the need for new defenses as these attacks can easily manipulate AI decision-making. With technology evolving rapidly, additional studies are planned, including tests in adverse weather conditions to assess AI resilience.
In summary, as AI continues to advance, understanding and addressing these vulnerabilities becomes crucial to ensure public safety and trust in automated systems. The methods developed by Cardenas and his team highlight not just the risks but also the paths we might take to defend against them.

