A few days ago Riley Goodside posted about an interesting discovery on how an LLM prompt injection can happen via invisible instructions in pasted text. This works by using a special set of Unicode code points from the Tags Unicode Block.
The proof-of-concept showed how a simple text contained invisible instructions that caused ChatGPT to invoke DALL-E to create an image.
Hidden Instructions for LLMs The meaning of these “Tags” seems to have gone through quite some churn, from language tags to eventually being repurposed for some emojis.