In web logs, what indicates a potential directory traversal attack?

The indication of a potential directory traversal attack is found in the request that contains the sequence of "../" in the URL. This attack method attempts to navigate the file system of a web server to access restricted files that should not be available through the web interface.

In the provided scenario, the request "GET http://example.com/viewarticle.php?view=../../../config.txt HTTP/1.1" shows evidence of this technique. The use of "../../../" suggests that the attacker is trying to ascend the directory structure, moving up three levels from the current directory, in an attempt to access the "config.txt" file located outside of the web root directory. If successful, this would expose sensitive configuration files which could contain critical information such as database credentials or server secrets.

In contrast, the other requests either do not attempt to access files outside of permitted directories or do not contain directory traversal patterns. The POST and GET requests to "http://example.com/login" and "http://example.com/home" indicate standard web application usage, while the DELETE request to "http://example.com/data/" is more concerned with resource manipulation rather than directory traversal. Thus, the presence of "../" in the URL for accessing a potentially sensitive file is what signals a directory traversal