CVE-2025-47287 Information

Description

Tornado is a Python web framework and asynchronous networking library. When Tornado’s multipart/form-data parser encounters certain errors it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous. All versions of Tornado prior to 6.5.0 are affected. The vulnerable parser is enabled by default. Upgrade to Tornado version 6.50 to receive a patch. As a workaround risk can be mitigated by blocking Content-Type: multipart/form-data in a proxy.

Reference

https://github.com/tornadoweb/tornado/commit/b39b892bf78fe8fea01dd45199aa88307e7162f3 https://github.com/tornadoweb/tornado/security/advisories/GHSA-7cx3-6m66-7c5m