multipart is a fast multipart/form-data parser for python. Prior to 1.2.2, 1.3.1 and 1.4.0-dev, the parse_options_header() function in multipart.py uses a regular expression with an ambiguous alternation, which can cause exponential backtracking (ReDoS) when parsing maliciously crafted HTTP or multipart segment headers. This can be abused for denial of service (DoS) attacks against web applications using this library to parse request headers or multipart/form-data streams. The issue is fixed in 1.2.2, 1.3.1 and 1.4.0-dev.

A vulnerability was found in Kong lua-multipart 0.5.8-1. It has been declared as problematic. This vulnerability affects the function is_header of the file src/multipart.lua. The manipulation leads to inefficient regular expression complexity. Upgrading to version 0.5.9-1 is able to address this issue. The patch is identified as d632e5df43a2928fd537784a99a79dec288bf01b. It is recommended to upgrade the affected component. VDB-220642 is the identifier assigned to this vulnerability.