0x0 App - System

vendredi 15 février 2019, 15:12  #1
App - System ELF x86 - Format string bug basic 1 (Password not accepted to validate)
Mr_Robot9874
  • 1 posts

By using %x I leaked the hex value of secret and changed its endianness. Something like this , if the leaked value is "4443424148474645" then after changing endianness it will be "ABCDEFGH" but when I try to submit that it says , "just try again " and hey just to confirm the length of the password is 12 , right ?

lundi 13 mai 2019, 14:17  #2
App - System ELF x86 - Format string bug basic 1 (Password not accepted to validate)
qmi
qmi
  • 7 posts

No :-... The leaked value is 4x8 bits (32) in hex. You’ll need to re-order the bytes due to little endian format. After that you’ll get the same no. of bits , but re-ordered. This starts with "4470...." and ends with "....0000" . You need to convert from hex format to plain text to get the final flag.

vendredi 17 mai 2019, 22:03  #3
App - System ELF x86 - Format string bug basic 1 (Password not accepted to validate)
Zlatan
  • 2 posts

Just a note, if someone is having trouble with this : you can find out the length of the string by looking at file it is stored. And if you are having hard time finding the string in memory, figure out what character is usually at the end of the file.