> For the complete documentation index, see [llms.txt](https://alham-rizvi.gitbook.io/alhamrizvi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://alham-rizvi.gitbook.io/alhamrizvi/binary-exp/03.-integer-overflow-md/challenge/easy/solution.md). # solution image This challenge demonstrates an **integer truncation vulnerability** caused by casting a user-controlled `int` to an `unsigned char`. The program checks admin access using the truncated value (`0–255`), but accepts any integer as input. Because of this, large values wrap around using modulo 256. By supplying a number like `456`, which becomes `200` after truncation (`456 % 256 = 200`), we satisfy the admin condition (`>= 200`) and bypass the access check. This shows that simply casting a value does not validate it, and improper handling of data types can lead to logic flaws and privilege escalation. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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, and the optional `goal` query parameter: ``` GET https://alham-rizvi.gitbook.io/alhamrizvi/binary-exp/03.-integer-overflow-md/challenge/easy/solution.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.