cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.40.0, cpp-httplib is vulnerable to HTTP Request Smuggling. The server's static file handler serves GET responses without consuming the request body. On HTTP/1.1 keep-alive connections, the unread body bytes remain on the TCP stream and are interpreted as the start of a new HTTP request. An attacker can embed an arbitrary HTTP request inside the body of a GET request, which the server processes as a separate request. This issue has been patched in version 0.40.0.
Exploitability
AV:NAC:HPR:NUI:NScope
S:UImpact
C:LI:LA:N4.8/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NOther