Maximmasiutin

An integer overflow exists in the string-to-integer conversion routine (` Val`). This allows a remote, unauthenticated attacker to bypass Content-Length restrictions and perform HTTP Request Smuggling. Successful exploitation can lead to unauthorized access, security filter bypass, and potential cache poisoning. The impact is critical for servers utilizing persistent connections (Keep-Alive).

TinyWeb, a web server for Win32, is susceptible to a header value confusion issue due to insufficient sanitization of control characters (CR, LF, and NUL, including encoded forms like %0d, %0a, and %00) within HTTP request headers. The parser's failure to strictly reject these characters and consistently defend against encoded forms can lead to unsafe data being introduced into the CGI execution context via HTTP * environment variables. This could potentially enable malicious manipulation of CGI processes.

TinyWeb, a web server for Win32, contains a flaw where unauthenticated remote attackers can circumvent the CGI parameter security controls. This can lead to source code disclosure or remote code execution (RCE), depending on the server’s configuration and the CGI executable being used. Systems hosting CGI scripts, such as PHP, are potentially affected. The issue is addressed in version 2.01.

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. The server creates a new operating system thread for each incoming connection without enforcing a maximum concurrency limit or an appropriate request timeout. An unauthenticated remote attacker can exhaust server concurrency limits and memory by opening numerous connections and sending data very slowly. This is known as a Slowloris attack. The `CMaxConnections` limit is set to 512 and the `CConnectionTimeoutSecs` idle timeout is set to 30 seconds in version 2.02.

TinyWeb is a web server written in Delphi for Win32. Versions prior to 2.02 are susceptible to a Denial of Service (DoS) condition caused by memory exhaustion. An unauthenticated remote attacker can send an HTTP POST request to the server with a very large `Content-Length` header, such as `2147483647`. The server allocates memory for the request body (`EntityBody`) continuously while processing the payload, without any size restrictions. This leads to the consumption of all available memory, ultimately causing the server to crash. Any service hosted using TinyWeb is potentially impacted. The issue is resolved in version 2.02, which introduces a `CMaxEntityBodySize` limit of 10MB for incoming payloads.

A vulnerability was found in the Request Handler component of Ritlabs TinyWeb Server. The manipulation with the input `%0D%0A` leads to CRLF injection. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.