BlockSec: BSC Chain MT Token Buy Limit Mechanism Flaw Exploited, Hacker Arbitrages Around $242,000

BlockBeats News, March 10th, according to BlockSec monitoring, its system detected a suspicious transaction targeting the MT-WBNB liquidity pool on BSC, with an estimated loss of about $242,000. The reason is due to a flaw in the buyer restriction mechanism: under deflationary mode, a normal buy operation would revert, but the router/trading pair was whitelisted, allowing the attacker to bypass restrictions through router swaps and liquidity removal to acquire 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, and then exchanged MT back to WBNB for profit. In addition, a recommended rule that allowed transferring the first 0.2 MT bypassed the buyer restriction, enabling the attacker to launch the attack.