✅Puzzle 6

overflow

Puzzle

############
# Puzzle 6 #
############

00      7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0      PUSH32 FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0
21      34                                                                      CALLVALUE
22      01                                                                      ADD
23      6001                                                                    PUSH1 01
25      14                                                                      EQ
26      602A                                                                    PUSH1 2A
28      57                                                                      JUMPI
29      FD                                                                      REVERT
2A      5B                                                                      JUMPDEST
2B      00                                                                      STOP

? Enter the value to send: (0) 

Solution

Pseudocode:

if (msg.value + 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0 == 0x01) {
    jump(0x2A);
}

This is an overflow. msg.value should be 17.