Poly Network

A $611M loss on multiple chains in 2021, caused by an access control flaw. Here's what happened, the vulnerability class behind it, and where it stands in ProveWall's re-proof pipeline.

$611Mreported loss

2021year

multiple chainschain

Access controlvulnerability class

Mechanism — keeper cross-contract -> forged cross-chain unlock

✔ Re-proven on a forked chain

We re-executed this exploit against the incident state on a forked chain; it moved value, and the patched control resisted. The signed, independently replayable receipt ships with the report.

What this class of bug is

Access-control flaws let an unauthorized caller reach privileged logic — minting, upgrading, unlocking, or draining funds — because a permission check is missing, wrong, or can be bypassed.

How to read this page. The dollar figure is the publicly reported loss attributed to this incident. A ProveWall re-proof reproduces the vulnerability class/mechanism by execution on a forked chain, with a signed receipt — we say so explicitly only once that execution has passed.

Other access control exploits

Same vulnerability class, re-proven or queued on the wall: Parity multisig freeze · Munchables

Want your own contract actually proven — not guessed?

Static tools and LLM auditors ask "is there a check here?" and miss the check that exists but is wrong. OmniGuard Labs runs the exploit on a forked chain and sends you a signed pass/fail receipt. Request a proof-backed audit →