OctoPrint versions up until and including 1.11.1 contain a vulnerability that allows any unauthenticated attacker to send a manipulated broken multipart/form-data request to OctoPrint and through that make the web server component become unresponsive. The issue can be triggered by a broken multipart/form-data request lacking an end boundary to any of OctoPrint's endpoints implemented through the octoprint.server.util.tornado.UploadStorageFallbackHandler request handler. The request handler will get stuck in an endless busy loop, looking for a part of the request that will never come. As Tornado is single-threaded, that will effectively block the whole web server. The vulnerability has been patched in version 1.11.2.

AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE-140

CWE-835

https://github.com/OctoPrint/OctoPrint/commit/c9c35c17bd820f19c6b12e6c0359fc0cfdd0c1ec

https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-9wj4-8h85-pgrw