On October 9, 2025, Astera was exploited through a liquidity index inflation attack, resulting in a loss of approximately $821,856 (8% of TVL) across three separate Minipools.
The vulnerability was an economic exploit combining the protocol's novel Minipool unwrapping mechanism and the flash loan fee mechanism to inflate the USDT liquidity index. All of these mechanics had previously been audited by top firms.
Following the exploit, $440,000 (54% of stolen funds) was rescued in collaboration with the Etherex and Linea teams and a further $380,000 (46% of stolen funds) was frozen by Linea’s security team.
Details of the exploit have been published in a previous post-mortem.
In keeping with our DeFi ethos, we tried our best to keep the unwind permissionless and decentralized, simply deactivating borrowing on the protocol and letting users unwind.
To keep the attacker from having asUSD swap routes, we maintained a 1:1 OTC program between USDC and asUSD via the Astera treasury.
Astera used its entire treasury to backfill all lost assets, take on any and all bad debt, and prioritize making users whole.
We maintain that Astera never has, and never will, sell any REX tokens to the open market.
This worked well until the attacker sold 440k asUSD in exchange for 3k USDC through the remains of the LP on Etherex.
This resulted in a significant inflation of asUSD liquidity at a fraction of the 1:1 price, that significantly complicated the process of unwinding Astera.
We were faced with users buying cheap asUSD and requesting 1:1 OTC from the remains of the treasury.
In order to protect remaining users and asUSD holders, we have taken a snapshot of all positions on Astera and executed a complete protocol asset borrow.
We apologize for not communicating this sooner, however we deemed that operational security was a priority.
The result is that Astera is fully wound down and we will OTC all collateral back to users in exchange for debt.
For users supplying with no debt, we will transfer your collateral back to you.
For users supplying collateral with non-asUSD debt, you can transfer debt assets directly to the treasury and we will transfer your collateral back to you.
For users supplying collateral with asUSD debt, you can transfer USDC to the treasury and we will return your collateral to you.