NCSC Warns Prompt Injection May Be Inherently Unfixable
⚠️ The UK National Cyber Security Centre (NCSC) warns that prompt injection vulnerabilities in large language models may never be fully mitigated, and defenders should instead focus on reducing impact and residual risk. NCSC technical director David C cautions against treating prompt injection like SQL injection, because LLMs do not distinguish between 'data' and 'instructions' and operate by token prediction. The NCSC recommends secure LLM design, marking data separately from instructions, restricting access to privileged tools, and enhanced monitoring to detect suspicious activity.
