CrossCTF_2017: Plebpwn

Category: Pwn Points: 10 Description:

Please pwn my plebian password program! Please connect to File here


A case of a buffer overflow attack though not obvious. Firstly, analysing the executable tells us that the buffer is 0x40 bytes long but the read() reads in 0x80 bytes. Trying to overflow 0x80 bytes crashes the application due to the overwriting of address of a string resulting in it crashing due to being unable to read from a location.


Therefore, the flag is CrossCTF{av01d_th0s3_cr4sh3s}.