BlockSec: Vulnerability in MT Token Purchase Restriction Mechanism on BSC Leads to Hacker Arbitrage of Approximately $242,000

Foresight News reported, according to monitoring by BlockSec, their system detected a suspicious transaction targeting the MT-WBNB liquidity pool on BSC, with an estimated loss of approximately $242,000. The cause was a flaw in the buyer restriction mechanism: under the deflationary mode, normal buy operations would be reverted, while routers/pairs were whitelisted, allowing the attacker to bypass restrictions through router swaps and liquidity removal to obtain MT from the pair.

The attacker then sold MT to accumulate pendingBurnAmount, and called distributeFees() to directly burn MT from the pair, artificially inflating the price, before swapping MT back to WBNB for profit. In addition, a recommended rule allowing the first 0.2 MT transfer to bypass buyer restrictions enabled the attacker to initiate the attack.