cryptomedium

AliEnS Challenge Scenario

HackTheBox

Task: attack an AES-ECB oracle with custom string padding and a fresh random key for every request. Solution: exploit the Unicode-versus-UTF-8 length mismatch to shift byte alignment, then recover the appended flag with same-request ECB block equality matching against a dictionary of candidate blocks.

$ ls tags/ techniques/
unicodeutf8aes_ecbchosen_plaintextcustom_paddingbyte_at_a_timeblock_alignment
same_request_ecb_block_matchingunicode_utf8_length_mismatch_abusemultibyte_alignment_shiftbyte_at_a_time_flag_recovery
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