Comment body XSS injection
An AI built this comment renderer so users can post markdown-ish HTML. It passed code review and shipped. Identify the vulnerability and what an attacker can do.
Implement
escape_comment_html(body: str) → strExamples
in
["hello world"]out"hello world"in
["line one\nline two"]out"line one<br/>line two"in
["<img src=x onerror=alert(1)>"]out"<img src=x onerror=alert(1)>"What a strong answer looks like
Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.
0:00 of about 20 min
Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.
Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.
Run or narrate your approach, then ask the coach.