Eclipse ThreadX NetX Duo HTTP Server Integer Underflow Vulnerability Leading to Denial-of-Service

A denial-of-service vulnerability has been identified in the HTTP server functionality of Eclipse ThreadX NetX Duo, in versions prior to 6.4.2. The issue arises in the handling of HTTP PUT requests, where an integer underflow can be exploited by sending specially crafted packets with a Content-Length smaller than the actual data being transmitted. This manipulation can cause a very large file to be written to the file system, potentially exhausting available resources and leading to a denial-of-service condition.

Impact

Exploitation of this vulnerability can cause a denial-of-service condition by consuming all available file system resources, which can disrupt normal operations and potentially cause applications to fail or behave unexpectedly.

Reproduction

To reproduce this vulnerability, send an HTTP PUT request with a Content-Length header that is smaller than the actual amount of data being sent. The server will process the request, leading to an integer underflow that allows an excessive amount of data to be written to the file system.

Remediation

Users can upgrade to Eclipse ThreadX NetX Duo version 6.4.2 or later to address this vulnerability. Additionally, for versions prior to 6.4.2, HTTP PUT support can be disabled as a workaround.