Collected research

Quicky Firefox DoS

Quicky Firefox DoS ha.ckers.org web application security lab

A four-line script hangs Firefox indefinitely: a loop to 65536 that appends one character at a time and calls document.write on the whole growing string each pass. The author expected the slow-script prompt and instead had to kill the process after ten minutes. The cost is quadratic rather than linear, as the comment thread works out.

Record

Document

Quicky Firefox DoS ha.ckers.org web application security lab

Published by

ha.ckers.org

Topic

HTTP

In the archive

• Collected in the 2009 research round

Tags

• dos
• javascript
• algorithmic-complexity
• dom
• owasp-a04-2021

This page is the archive's own catalogue record. The research is the work of ha.ckers.org, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 16 August 2026.