Metasploit Revealed: Secrets of the Expert Pentester

Determining bad characters

Sometimes it may happen that after setting up everything right for exploitation, we may never get to exploit the system. Alternatively, it might happen that our exploit has completed but the payload fails to execute. This can happen in cases where the data supplied in the exploit is either truncated or improperly parsed by the target system causing unexpected behavior. This will make the entire exploit unusable and we will struggle to get the shell or meterpreter onto the system. In this case, we need to determine the bad characters that are preventing the execution. To handle such situations, the best method is to find matching similar exploit and use the bad characters from it in your exploit.

We need to define ...