> For the complete documentation index, see [llms.txt](https://reports.immunefi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://reports.immunefi.com/folks-finance-staking-contracts/69673-sc-low-users-cannot-revoke-a-migration-permit-after-role-removal.md). # 69673 sc low users cannot revoke a migration permit after role removal **Submitted on Mar 16th 2026 at 07:47:51 UTC by @Athenea for** [**Audit Comp | Folks Finance: Staking Contracts**](https://immunefi.com/audit-competition/audit-comp-folks-finance-staking-contracts) * **Report ID:** #69673 * **Report Type:** Smart Contract * **Report severity:** Low * **Target:** ## Description ### Brief/Intro This insight highlights a user-control issue in the migration permission system. Once a migrator loses `MIGRATOR_ROLE`, users who had previously approved it can no longer explicitly revoke that approval, leaving stale permissions in storage. ### Vulnerability Details `setMigrationPermit()` requires the target address to currently hold `MIGRATOR_ROLE` for both enabling and disabling a permit: ```solidity function setMigrationPermit(address _migrator, bool _isMigrationPermitted) external { if (!hasRole(MIGRATOR_ROLE, _migrator)) revert MigratorNotFound(_migrator); migrationPermits[_migrator][msg.sender] = _isMigrationPermitted; emit MigrationPermitUpdated(_migrator, msg.sender, _isMigrationPermitted); } ``` As a result, once a migrator loses `MIGRATOR_ROLE`, users who previously approved it can no longer explicitly revoke that approval. ### Impact Details This is not an immediate exploit, because a role-revoked migrator cannot call `migratePositionsFrom()` while the role is absent.\ Still, the behavior weakens user control and leaves stale approvals in place until role configuration changes again. ### References ### Recommendation Require `MIGRATOR_ROLE` only when enabling a permit, not when disabling one: ```solidity function setMigrationPermit(address _migrator, bool _isMigrationPermitted) external { if (_isMigrationPermitted && !hasRole(MIGRATOR_ROLE, _migrator)) { revert MigratorNotFound(_migrator); } migrationPermits[_migrator][msg.sender] = _isMigrationPermitted; emit MigrationPermitUpdated(_migrator, msg.sender, _isMigrationPermitted); } ``` ## Proof of Concept ### Steps 1. Deploy `Staking`. 2. Grant `MIGRATOR_ROLE` to `migrator`. 3. User enables migration permit for `migrator`. 4. Admin revokes `MIGRATOR_ROLE` from `migrator`. 5. User tries to disable the permit. ### Code Git Url: ```solidity pragma solidity ^0.8.23; import {console2} from "forge-std/console2.sol"; import {BaseInsightScript, PoCToken} from "../src/InsightPoCHelpers.sol"; import {Staking} from "repo-src/Staking.sol"; contract RevokePermitAfterRoleRemoval is BaseInsightScript { function run() external { _selectForkIfConfigured(); console2.log("=== Insight 1: Revoke permit fails after role removal ==="); (Staking staking, PoCToken token) = _deployStakingFixture(); token; bytes32 migratorRole = staking.MIGRATOR_ROLE(); vm.prank(USER_A); staking.setMigrationPermit(MIGRATOR, true); console2.log("Step 1: USER_A enabled migration permit for MIGRATOR"); vm.prank(ADMIN); staking.revokeRole(migratorRole, MIGRATOR); console2.log("Step 2: ADMIN revoked MIGRATOR_ROLE"); vm.prank(USER_A); (bool success, bytes memory lowLevelData) = address(staking).call(abi.encodeCall(staking.setMigrationPermit, (MIGRATOR, false))); if (success) { console2.log("Unexpected: permit revocation succeeded"); } else { console2.log("Step 3: USER_A tried to disable the permit and the call reverted"); console2.logBytes(lowLevelData); } } } ``` ### Result Script ran successfully. Gas used: 5623713 ``` == Logs == Fork selected from BSC_RPC_URL === Insight 1: Revoke permit fails after role removal === Step 1. USER_A enabled migration permit for MIGRATOR Step 2. ADMIN revoked MIGRATOR_ROLE Step 3. USER_A tried to disable the permit and the call reverted 0x881da127000000000000000000000000000000000000000000000000000000000000000e ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. 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