Protocol Upgrade Compatibility Review: Sentora Curator

The Sentora Curator protocol, a multi-chain liquidity-curation platform, is set to undergo a major upgrade. This upgrade brings several changes, including a migration to a new UUPS‑proxy implementation, introduction of a quadratic‑voting module, a replacement of the legacy bridge with a zk‑rollup‑compatible bridge contract, and a dynamic fee model based on an on‑chain volatility oracle. The protocol also incorporates an Emergency Pause feature that can be triggered by a multi‑sig (3‑of‑5).

The review highlights several key findings concerning upgrade-compatibility risks. These risks are categorized as Critical, High, Medium, and Low. The highest severity issue is a storage‑layout collision with a severity rating of Critical (9/10). This issue arises because the new implementation adds three state variables before the existing feeRecipient slot, resulting in a storage shift that could corrupt fee accounting and bridge balances.

If the proxy is upgraded without proper storage‑gap migration, it could lead to the loss or corruption of up to $1 billion in assets.

Other notable issues include an unrestricted delegatecall in the bridge, which poses a high risk of arbitrary code execution and potential theft of up to $500 million in bridge assets. The reduction in governance timelock from 72 hours to 12 hours also poses a high risk, as it allows a compromised admin more time to execute malicious code. Additionally, the zk‑bridge lacks per‑chain nonce, creating a medium risk of replay attacks that could result in double‑spending of up to $200 million.

The protocol’s emergency pause feature has a low risk rating of Low (3/10) but still warrants attention due to the lack of a cool‑down period after a pause is lifted. This could allow an attacker to repeatedly pause and unpause the protocol, potentially leading to front‑running and market manipulation. Other technical recommendations include safely migrating the storage layout, restricting delegatecall in the bridge, and enforcing proper access controls on the setFeeRecipient function.

Overall, the protocol-level risk from the upgrade is rated at 7.2/10, indicating a high level of risk. The most urgent remediation required is addressing the storage‑layout issue, which alone could corrupt up to $1 billion of assets.