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Poly Network: Cross-chain Message Forgery — Privileged Contract Caller Manipulation

Poly Network lost $611M — the largest crypto hack ever at the time — when an attacker exploited a cross-chain message routing flaw to replace the bridge's keeper keys with their own, then returned every dollar days later claiming it was done "for fun."

Occurred 2021-08-11 Loss $611M Status closed

Summary #

Poly Network suffered a Cross-chain Bridge on 2021-08-11, resulting in a loss of approximately $611M.

What happened #

Poly Network lost $611M — the largest crypto hack ever at the time — when an attacker exploited a cross-chain message routing flaw to replace the bridge's keeper keys with their own, then returned every dollar days later claiming it was done "for fun."

Linked factors #

  • RD-F-007 — related : Bug bounty absent — baseline integrity gap [via dashboard_risk_factors/Bug bounty: Unknown]