Denial Of Service (DoS)

Tornado is vulnerable to Denial of Service DoS. The vulnerability is due to inefficient string concatenation in the HTTPHeaders.add method when processing repeated HTTP headers, which allows an attacker to send a crafted request that blocks the server's event loop and exhausts CPU resources...

tornado: Tornado Quadratic DoS via Repeated Header Coalescing

A denial of service flaw has been discovered in the Tornado networking library. In Tornado, a single maliciously crafted HTTP request can block the server's event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the...