Klever-Go Account takeover: `kleverUpdateAccountPermission` authorizes on attacker-controlled `RecipientAddr` instead of the authenticated caller

QFinch assessment

The VM built-in function `KleverUpdateAccountPermission` (registered always-active, `creator.go:381-390` / `core/vmconstants.go:234`) rewrites an account's entire permission set. Its authorization check uses `vmInput.RecipientAddr` **attacker-controlled** instead of the authenticated `vmInput.CallerAddr`. The sibling handler `kleverChangeOwnerAddress.go:86` uses `vmInput.CallerAddr` correctly, so the safe pattern exists in-repo; this handler deviates. The native transaction path (`txProcess.go:833`) is safe it uses `tx.GetSender()`.

Potential impact

Full takeover of any account that has configured permissions i.e. every multisig / advanced-permission account , by an attacker who deploys a cheap smart contract and supplies only public on-chain addresses (no keys, no signatures from the victim). After takeover the attacker controls all of the victim's operations → theft or permanent lock of all the account's assets. Reachable via a permissionlessly-deployed contract (the plain-tx path is safe, so it is Critical-via-contract, not fully no-contract). No fork flag gates it. Severity Critical: Impact High (full account/asset compromise)