# Use-After-Free Much like the name suggests, this technique involves us *using data once it is freed*. The weakness here is that programmers often wrongly assume that once the chunk is freed it cannot be used and don't bother writing checks to ensure data is not freed. This means it is possible to write data to a free chunk, which is very dangerous. TODO: binary --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://ir0nstone.gitbook.io/notes/binexp/heap/use-after-free.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.