Summary
The IBlockHashRetain.vyi interface exposes significant centralization risks and lacks proper access control mechanisms, particularly in the commit and apply functions.
Vulnerability Details
Current implementation shows dangerous centralization points:
@external
def commit() -> uint256:
"""
@notice Commit (and apply) a block hash/state root.
@dev Same as `apply()` but saves committer
"""
# No role-based access control
# Single point of failure for commits
...
@external
def apply() -> uint256:
"""
@notice Apply a block hash/state root.
"""
# No multi-sig requirement
# No timelock protection
...
Critical issues:
Single admin control
No delay mechanisms
Missing role separation
Lack of multi-sig requirements
No governance oversight
Impact
Single point of failure risks
Potential admin key compromise
Unauthorized state modifications
No consensus requirements
Immediate critical changes possible
Tools Used
Recommendations
Implement comprehensive role-based access control:
# Role definitions
ADMIN_ROLE: constant(bytes32) = keccak256("ADMIN_ROLE")
OPERATOR_ROLE: constant(bytes32) = keccak256("OPERATOR_ROLE")
VALIDATOR_ROLE: constant(bytes32) = keccak256("VALIDATOR_ROLE")
# Access control state
roles: public(HashMap[bytes32, HashMap[address, bool]])
role_member_count: public(HashMap[bytes32, uint256])
min_validators: public(uint256)
@external
def initialize_roles(_admin: address):
"""
@notice Initialize role system
"""
assert self.role_member_count[ADMIN_ROLE] == 0, "Already initialized"
self.roles[ADMIN_ROLE][_admin] = True
self.role_member_count[ADMIN_ROLE] = 1
self.min_validators = 3
Add multi-sig functionality:
struct Proposal:
id: uint256
proposer: address
block_number: uint256
hash: bytes32
approvals: uint256
executed: bool
deadline: uint256
proposals: public(HashMap[uint256, Proposal])
next_proposal_id: public(uint256)
proposal_approvals: public(HashMap[uint256, HashMap[address, bool]])
@external
def propose_commit(_block_number: uint256, _hash: bytes32) -> uint256:
"""
@notice Propose a new commit with multi-sig requirement
"""
assert self.roles[VALIDATOR_ROLE][msg.sender], "Not validator"
proposal_id: uint256 = self.next_proposal_id
self.next_proposal_id = proposal_id + 1
self.proposals[proposal_id] = Proposal({
id: proposal_id,
proposer: msg.sender,
block_number: _block_number,
hash: _hash,
approvals: 1,
executed: False,
deadline: block.timestamp + 86400 # 24 hour deadline
})
self.proposal_approvals[proposal_id][msg.sender] = True
return proposal_id
Implement timelock protection:
TIMELOCK_DELAY: constant(uint256) = 86400 # 24 hours
struct TimelockOperation:
target: address
value: uint256
data: Bytes[1024]
execution_time: uint256
executed: bool
timelock_ops: public(HashMap[bytes32, TimelockOperation])
@external
def queue_operation(_target: address, _value: uint256, _data: Bytes[1024]) -> bytes32:
"""
@notice Queue operation with timelock
"""
assert self.roles[ADMIN_ROLE][msg.sender], "Not admin"
op_id: bytes32 = keccak256(concat(
convert(_target, bytes32),
convert(_value, bytes32),
_data
))
self.timelock_ops[op_id] = TimelockOperation({
target: _target,
value: _value,
data: _data,
execution_time: block.timestamp + TIMELOCK_DELAY,
executed: False
})
return op_id
Add governance controls:
struct GovernanceConfig:
min_quorum: uint256
voting_period: uint256
execution_delay: uint256
governance_config: public(GovernanceConfig)
@external
def update_system_params(_new_params: GovernanceConfig) -> bool:
"""
@notice Update system parameters through
"""
assert self.roles[ADMIN_ROLE][msg.sender], "Not admin"
assert self._check_quorum(), "Insufficient quorum"
assert self._validate_params(_new_params), "Invalid params"
op_id: bytes32 = self.queue_operation(
self.address,
0,
_new_params
)
return True
@internal
def _check_quorum() -> bool:
"""
@notice Check if quorum is reached
"""
return self.role_member_count[VALIDATOR_ROLE] >= self.governance_config.min_quorum
These enhancements provide:
Distributed control through roles
Multi-signature requirements
Timelock protection
Governance oversight
Quorum validation
Clear separation of duties
