An attack of this type exploits a system's configuration that allows an adversary to either directly access an executable file, for example through shell access; or in a possible worst case allows an adversary to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.

Not present

1. System's configuration must allow an attacker to directly access executable files or upload files to execute. This means that any access control system that is supposed to mediate communications between the subject and the object is set incorrectly or assumes a benign environment.

1. Ability to communicate synchronously or asynchronously with server that publishes an over-privileged directory, program, or interface. Optionally, ability to capture output directly through synchronous communication or other method such as FTP.

1. Consider a directory on a web server with the following permissions drwxrwxrwx 5 admin public 170 Nov 17 01:08 webroot This could allow an attacker to both execute and upload and execute programs' on the web server. This one vulnerability can be exploited by a threat to probe the system and identify additional vulnerabilities to exploit.