On February 3, 2022, Jump Trading, the parent company of Wormhole, attempted to reach out to the attacker by offering a $10 million bounty in exchange for the return of the stolen assets. Unfortunately, this offer was met with silence.<\/li><\/ul>\n\n\n\nAttack Technical Analysis<\/h3>\n\n\n\n
The attacker meticulously executed a series of steps to exploit vulnerabilities within the Wormhole bridge’s verification process:<\/p>\n\n\n\n
Step 1: Spoofed “verify_signatures” Function<\/strong><\/p>\n\n\n\n- The attacker initiated the attack by invoking the “verify_signatures” function. This function is integral to the verification process and plays a critical role in ensuring the authenticity of transactions.<\/li>
- Within this function, a malicious “Sysvar account” was introduced to deceive the system. You can view the transaction here: (https:\/\/solscan.io\/tx\/25Zu1L2Q9uk998d5GMnX43t9u9eVBKvbVtgHndkc2GmUFed8Pu73LGW6hiDsmGXHykKUTLkvUdh4yXPdL3Jo4wVS).<\/li><\/ul>\n\n\n\n
![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-2-1024x574.png\")
<\/figure>\n\n\n\nStep 2: Counterfeit “verify_signatures” Function<\/strong><\/p>\n\n\n\n- The attacker employed a counterfeit “verify_signatures” function with the injected malicious “sysvar account.” This deceptive function aimed to subvert the verification process and grant the attacker unauthorized access.<\/li>
- A genuine “verify_signatures” function with a legitimate “Sysvar account” is shown for reference.<\/li><\/ul>\n\n\n\n
![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-3-1024x561.png\")
<\/figure>\n\n\n\nStep 3: Exploiting “load_current_index” Vulnerability<\/strong><\/p>\n\n\n\n- Within the legitimate “verify_signatures” function, the system typically loads the current instructions from the Sysvar, specifically at instruction L92.<\/li>
- However, a critical vulnerability was exposed in the function “load_current_index.” This vulnerability failed to validate whether the injected “Sysvar account” corresponded to the authentic “system sysvar.”<\/li>
- As the current instruction (L92) retrieved from the “sysvar” was under the attacker’s control, it enabled the attacker to manipulate the verification process with impunity.<\/li><\/ul>\n\n\n\n
![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-4-1024x548.png\")
<\/figure>\n\n\n\nStep 4: Malicious “post_vaa” Function<\/strong><\/p>\n\n\n\n- With the verification process compromised, the attacker proceeded to invoke the “post_vaa” function using the verified signatures obtained in the previous step.<\/li>
- Within this action, the attacker created a malevolent message account specifying the minting of 120,000 wETH. The transaction can be viewed here: (https:\/\/solscan.io\/tx\/2SohoVoPDSdzgsGCgKQPByKQkLAXHrYmvtE7EEqwKi3qUBTGDDJ7DcfYS7YJC2f8xwKVVa6SFUpH5MZ5xcyn1BCK).<\/li><\/ul>\n\n\n\n
![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-5-1024x452.png\")
<\/figure>\n\n\n\nStep 5: Executing “complete_wrapped” Function<\/strong><\/p>\n\n\n\n- Building on the foundation established in the previous steps, the attacker proceeded to invoke the “complete_wrapped” function.<\/li>
- This function processed the data contained within the malicious message account created in the “post_vaa” step, culminating in the minting of 120,000 wETH tokens. The transaction details can be found here: (https:\/\/solscan.io\/tx\/2zCz2GgSoSS68eNJENWrYB48dMM1zmH8SZkgYneVDv2G4gRsVfwu5rNXtK5BKFxn7fSqX9BvrBc1rdPAeBEcD6Es).<\/li><\/ul>\n\n\n\n
![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-6-999x1024.png\")
<\/figure>\n\n\n\nStep 6: Asset Movements<\/strong><\/p>\n\n\n\n- Following the minting of wETH, the attacker orchestrated a series of asset movements:<\/li>
- Some of the minted wETH tokens were transferred to the Ethereum blockchain.<\/li>
- The remaining wETH tokens were exchanged for USDC and SOL on the Solana blockchain, utilizing various transactions:<\/li><\/ul>\n\n\n\n
- https:\/\/solscan.io\/tx\/j3jUDG43di8Dsg7Q3jQhstamtBovu1GLqnDJ7yNvM3r4pnK9e7uqgt9uBobCjT5S1BKhZZFQNQwDxypEYqLknec<\/li>
- https:\/\/solscan.io\/tx\/5UaqPus91wvAzKNve6L8YAHsESomZQ7GWi37gPFyzTHcXNMZA641bb8m8txo7bS7A5cAnzKDKYyiKcQC8GgDcAuf<\/li>
- https:\/\/solscan.io\/tx\/3AugXqrXunBa96YfqENhPBiWZWpnSnJdqAHS64qcHTVU9KtfGon8cN9cUuXsDmBobBBXjYUtuRxnYxgERS42nh6G<\/li>
- https:\/\/solscan.io\/tx\/2SndtH3tU4j6v14HJzEde3d3dnpdHqTPn4VnvhTj4zKLo26H5kmtCwjn2nANfjXNVbmFsyEGtD4Jte25azsPwaRk<\/li><\/ol>\n\n\n\n
<\/p>\n\n\n\n
Contract Vulnerability Analysis<\/h3>\n\n\n\n
The underlying cause of this exploit can be attributed to a critical oversight within the verification process, specifically within the “verify_signatures”<\/strong> function. The flaw resided in the usage of the deprecated function “load_current_index”<\/strong> which failed to validate the authenticity of the provided “sysvar account.” Consequently, the attacker could manipulate this critical account, enabling the successful execution of the exploit.<\/p>\n\n\n\n![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-7-1024x746.png\")
<\/figure>\n\n\n\n
![\"\"](\"https:\/\/www.trustrecipe.in\/wp-content\/uploads\/2023\/09\/Wormhole-Bridge-Hack-1.png\")
<\/figure>\n\n\n\n