• running the cat.elf binary prompts for a password

• however, by using ltrace ./cat.elf while the program is running, we’re able to see that the validation is made by the strcmp function ;

chmod +x cat.elf
madalinux@asgard:~/workspace/ctf_workspace$ ltrace ./cat.elf
puts("https://www.youtube.com/watch?v="...https://www.youtube.com/watch?v=oHg5SJYRHA0
)                                                                = 44
printf("The password is: ")                                                                                = 17
__isoc99_scanf(0x562134000a56, 0x7ffeb325c0a0, 0, 0The password is: 7481
)                                                       = 1
strcmp("7481", "{redacted}")                                                                                 = -57

NOTE: for you own safety, don’t open that youtube link :)

• Run the program again and use the password found in the strcmp function as input to get the flag.