Starlet versions from 0.20 before 0.33 for Perl allow memory exhaustion via unbounded buffering when decoding chunked request bodies.

The decoder adds each read to one buffer of unconsumed input. Nothing limits the length of a chunk-size line, so a line without a CRLF grows the buffer for as long as the client keeps sending, and the read timeout restarts after every read. The data of a large chunk is also held in the buffer until the whole chunk has arrived.

A remote attacker can exhaust a worker's memory with a single request.