CVE-2004-2140

Vulnerability

A CRLF injection vulnerability exists in YaBB 1 Gold versions prior to 1.3.2. The flaw resides in how the application handles the subject variable. By injecting carriage return and line feed characters into this parameter, a remote attacker can manipulate the contents of text files on the server. This is a classic injection issue in the bulletin board software's input processing.

Exploitation

An attacker does not need authentication; they can exploit this remotely over HTTP. The attacker crafts a request to a vulnerable YaBB installation, injecting CRLF sequences into the subject field. This allows the injection of arbitrary lines into server-side text files that the application writes to (e.g., log files or configuration files). No special privileges or elevated access aside from network connectivity are required.

Impact

Successful exploitation lets the attacker write arbitrary data to text files accessible by the web server process. This can lead to defacement, injection of malicious scripts, or modification of application behavior if those files are later interpreted. The CIA impact primarily targets integrity and may lead to data corruption or further compromise depending on the file contents.

Mitigation

The vulnerability is fixed in YaBB 1 Gold version 1.3.2 [1]. Users should upgrade immediately to this or any later version. No alternative workarounds are documented in the available references; as the product may be end-of-life, no future patches are expected for older versions [1].