CyberRota Analysis
AI-GeneratedVersions of Reverse::Proxy prior to 0.04 for Perl are vulnerable to HTTP request smuggling due to improper handling of the PATH_INFO variable, which allows attackers to craft malicious requests that can manipulate the upstream server's request processing. This vulnerability can lead to unauthorized access to resources and potential exploitation of the upstream application, as the proxy fails to validate or re-encode critical request components. Organizations using affected versions should prioritize remediation to prevent exploitation, especially those relying on Perl-based web applications that utilize this proxy functionality.
Original NVD Description
Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line. PSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, '?' or '#' truncates it the same way. Everything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy's own routing does not expose.