HTTP::Body versions before 1.23_01 for Perl allow memory exhaustion via an unbounded multipart part header block. The multipart parser takes everything up to the first blank line after a boundary as the part's header block, with no limit on its size or number of lines. Every line is stored in the part's header hash, so a block of short lines costs about 60 bytes of memory per input byte. A remote attacker can exhaust worker memory with a single request.