GSN forwarder skips signature check, relying solely on attacker-chosen paymaster
מה ידוע על המתקפה?
הסיווג ושיטת התקיפה משקפים את דיווחי המקורות. תיאורים מפורטים מוצגים בשפת המקור; לקריאת התחקיר המלא ניתן לפתוח את הקישור המצורף.
DefiLlamaתיאור המקור באנגלית
Nimiq’s Polygon swap contracts served as OpenGSN forwarders while relying on their own preRelayedCall path to authenticate requests rather than independently verifying the user’s signature inside execute(). An attacker registered an EIP-7702 EOA as an OpenGSN relay manager, relay worker and permissive paymaster, then selected Nimiq’s HTLC handlers as the forwarders. This allowed forged open() requests purportedly originating from a partner liquidity wallet to reach the handlers without the expected signature validation. Because that wallet had existing token approvals to the handlers, HTLCs were opened using its USDC, USDT0 and USDC.e, with the attacker-controlled contract as recipient, and subsequently redeemed by the attacker
SlowMistתיאור המקור באנגלית
An attacker abused an OpenGSN meta-transaction auth flaw on Polygon HTLC contracts: open/execute accepted a spoofed from without a real user signature. Posing as liquidity wallet 0x24cb…6773, they used leftover near-unlimited ERC-20 allowances to lock 26,130.64171 USDC, 24,332.489269 USDT0 and 0.661117 USDC.e into HTLCs with attacker-chosen recipient and secretHash=sha256(1), then redeemed via a CREATE2 contract with secret=1. Single-tx loss was about $50,463.
GSN forwarder skips signature check, relying solely on attacker-chosen paymaster
מה ידוע על המתקפה?
הסיווג ושיטת התקיפה משקפים את דיווחי המקורות. תיאורים מפורטים מוצגים בשפת המקור; לקריאת התחקיר המלא ניתן לפתוח את הקישור המצורף.
DefiLlamaתיאור המקור באנגלית
Nimiq’s Polygon swap contracts served as OpenGSN forwarders while relying on their own preRelayedCall path to authenticate requests rather than independently verifying the user’s signature inside execute(). An attacker registered an EIP-7702 EOA as an OpenGSN relay manager, relay worker and permissive paymaster, then selected Nimiq’s HTLC handlers as the forwarders. This allowed forged open() requests purportedly originating from a partner liquidity wallet to reach the handlers without the expected signature validation. Because that wallet had existing token approvals to the handlers, HTLCs were opened using its USDC, USDT0 and USDC.e, with the attacker-controlled contract as recipient, and subsequently redeemed by the attacker
SlowMistתיאור המקור באנגלית
An attacker abused an OpenGSN meta-transaction auth flaw on Polygon HTLC contracts: open/execute accepted a spoofed from without a real user signature. Posing as liquidity wallet 0x24cb…6773, they used leftover near-unlimited ERC-20 allowances to lock 26,130.64171 USDC, 24,332.489269 USDT0 and 0.661117 USDC.e into HTLCs with attacker-chosen recipient and secretHash=sha256(1), then redeemed via a CREATE2 contract with secret=1. Single-tx loss was about $50,463.
