[AUDIT] 2 CRITICAL + 3 HIGH — Sequencer Vault Drain + DA Manipulation (Code Validated)

[perihrmwn]

Summary

2 Critical, 3 High, 5 Medium, 4 Low findings. Validated by code analysis (Solana, settlement + DA log + SDK).

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Validation Method

Full source audit of programs/zul-settlement/src/lib.rs (617 lines), programs/zul-da-log/src/lib.rs (69 lines), programs/smt/src/lib.rs (244 lines), and SDK files.

Findings

C1 (CRITICAL): Sequencer Can Drain Bridge Vault via Arbitrary Root Posting

post_batch accepts state_root and withdrawals_root as raw byte arrays with ZERO on-chain validation. No fraud proof, no challenge window, no ZK proof.

Attack Path:

1. Sequencer calls post_batch(withdrawals_root = crafted_root) with fake withdrawal commitment
2. Anyone calls claim_withdrawal(proof against crafted_root) — proof verifies against sequencer-controlled root
3. Vault drains all funds

C2 (CRITICAL): No Vault Balance Check on Claim

claim_withdrawal does not check vault has sufficient lamports before transfer.

H1 (HIGH): DA Log Fully Permissionless — Fake Data Injection

No authority check, no batch existence check, no data validation on post_chunk.

H2 (HIGH): Claim PDA Doesn't Bind batch_no — Cross-Batch Replay

Claim PDA derived from [CLAIM_SEED, recipient, nonce] — no batch_no.

H3 (HIGH): Sequencer Can Mint Unbacked Wrapped Tokens on L2

L2 state entirely controlled by sequencer. Can credit tokens without corresponding L1 deposits.