$ ctf42

Blockchain CTF challenges

215 Blockchain CTF challenges from 63 CTFs (2022–2026), 91 with writeups.

Top blockchain techniques

#smart-contract 4 #cairo-starknet-contract-reversing 1 #ethereum-storage-read 1 #private-variable-exposure 1 #token-economy-logic-flaw 1 #signed-integer-overflow 1 #integer-overflow 1 #weak-prng 1 #arbitrary-storage-write 1 #storage-reading 1 #predictable-blockchain-rng 1 #merkle-proof 1 #private-storage-read 1 #flash-loan 1 #reentrancy 1

Challenges

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Challenge CTF Weight Has
infinite
#smart-contract#token-economy-logic-flaw
 CrewCTF 2023 20.33 files wu 3
Pigeon_Bank
#smart-contract#reentrancy#flash-loan
 SEETF 2023 – files wu 3
Murky_SEEPass
#smart-contract#merkle-proof#private-storage-read
 SEETF 2023 – files wu 3
World_of_Ottercraft
#move-state-machine
 justCTF 2024 Quals 77.17 files wu 3
Dark_BrOTTERhood
#move-access-control
 justCTF 2024 Quals 77.17 files wu 3
positive
#integer-overflow#signed-integer-overflow
 CrewCTF 2023 20.33 files wu 3
The_Otter_Scrolls
#hardcoded-secret
 justCTF 2024 Quals 77.17 files wu 3
deception
#ethereum-storage-read#private-variable-exposure
 CrewCTF 2023 20.33 files wu 3
The_Timekeepers_Paradox COMPFEST 2026 – files wu 3
flashy MidnightFlag 2026 24.50 files wu 3
Nusantara_Fortune_Pool TheCyberJawaraInternational 2024 23.62 files wu 3
SafeBridge RealWorld 2024 – files wu 3
Advance_Vault WannaGameChampionship 2023 – files wu 3
BabyBlackjack BackdoorCTF 2023 – files wu 3
Basic_Vault WannaGameChampionship 2023 – files wu 3
ChairLift Glacier 2023 24.32 files wu 3
GlacierCoin Glacier 2023 24.32 files wu 3
GlacierVault Glacier 2023 24.32 files wu 3
Pigeon_Vault SEETF 2023 – files wu 3
The_Council_of_Apes Glacier 2023 24.32 files wu 3
realwrap RealWorld 2023 – files wu 3
AAADAO AzureAssassinAlliance 2022 23.80 files wu 3
Weird_EVM AzureAssassinAlliance 2022 23.80 files wu 3
bread_bank X-MAS 2022 – files wu 3
proposal_unlock NahamCon 2022 EU 24.61 files wu 3
CryptoCasino
#weak-prng
 DownUnderCTF 2022 – files wu 2
baby-wallet
#smart-contract-logic-error
 corCTF 2023 36.97 files wu 2
Immutable
#metamorphic-contract
 LakeCTF 2022 Quals 23.96 files wu 2
QuinEVM
#evm-quine
 LakeCTF 2022 Quals 23.96 files wu 2
BlockJail COMPFEST 2026 – files wu 2
Gateway CSS 2026 – files wu 2
Lottery CSS 2026 – files wu 2
Phantom_Ledger COMPFEST 2026 – files wu 2
heist_v1 EHAX 2026 – files wu 2
Dinosaur_Park WorldWide 2025 24.48 files wu 2
Ode GCC 2024 – files wu 2
Play_to_Earn SekaiCTF 2024 36.96 files wu 2
TOOTB GCC 2024 – files wu 2
burgercoin b01lers 2024 30.80 files wu 2
rankpls osuigaming 2024 – files wu 2