nimcontroller_bof: return CheckCode::Unknown if response is empty

[bcoles]

Patch implemented based on source code review. Untested but apparently this patch works. #14462

[gwillcox-r7]

Looks good to me. Was going to ask about potentially changing the line if target['Version'].in? response to if target['Version'].in? response.to_s since this was in the issue you linked to but the .in? method ultimately relies on .include? which both strings and arrays should implement, so I can see why you might of decided to leave this out.

[gwillcox-r7]

Okay one thing I did notice was that whilst this code works the output is a little awkward to read. Here is the line I get in the console when this is hit:

[-] 127.0.0.1:48000 - Exploit aborted due to failure: unknown: Cannot reliably check exploitability. No response Enable ForceExploit to override check result.

Going to make a small ninja edit to make the message that is output a little bit easier to understand in the context of all the other code. Otherwise this new code was confirmed to prevent the case where response is not a valid string or array and then the code attempts to call the .in? method on it.

[gwillcox-r7]

Release Notes

Fixed the exploits/windows/nimsoft/nimcontroller_bof module to implement a missing check for cases where a server may disconnect during the execution of the check method, which may cause the response object to be empty or nil. The new code within the check method will now ensure a CheckCode::Unknown error is appropriately thrown in these instances to let the user know that it was not possible to determine if the target is exploitable or not as the server disconnected during the execution of the check method.