Part 2

Summary

A critical security vulnerability has been discovered in the WithdrawalRequest library's load() function, where unchecked inline assembly operations allow direct storage pointer manipulation. This vulnerability enables attackers to potentially access and manipulate withdrawal requests belonging to other users, compromising the integrity of the entire system.

Vulnerability Details

Location:

Technical Analysis:

• The function uses inline assembly to directly manipulate storage pointers

• No validation exists for the computed storage slot

• Predictable slot calculation pattern enables collision attacks

• Pure function modifier prevents state validation

Root Cause Analysis

1. Direct Storage Manipulation - Inline assembly bypasses Solidity's safety checks

• Storage pointer assignment without validation

• Missing bounds checking on computed slots

1. State Validation Issues - Pure function modifier prevents state verification

• No initialization checks on storage slots

• Missing access control mechanisms

Impact Assessment

Severity: Critical

Potential Attacks:

1. Unauthorized Access to Withdrawal Requests

2. Fund Theft Through Request Manipulation

3. Data Tampering and Integrity Breaches

4. Denial of Service Attacks

Business Impact:

• Financial losses through unauthorized withdrawals

• System reputation damage

• Loss of user trust

• Potential regulatory compliance issues

Tools Used

• Static analysis tools for initial detection

• Manual code review for vulnerability verification

• Foundry test framework for proof of concept

• Assembly-level debugging tools

Proof of Concept

Here's a Foundry test demonstrating the vulnerability:

Mitigation Recommendations

1. Immediate Fixes:```solidity
   library WithdrawalRequest {
   // Add unique salt to prevent collisions
   bytes32 private constant STORAGE_SLOT_SALT = keccak256("WithdrawalRequest.v2");

   function load(
   uint128 vaultId,
   address account,
   uint128 withdrawalRequestId
   ) internal view returns (Data storage withdrawalRequest)
   {
   bytes32 slot = keccak256(abi.encodePacked(
   STORAGE_SLOT_SALT,
   WITHDRAWAL_REQUEST_LOCATION,
   vaultId,
   account,
   withdrawalRequestId
   ));

   // Remove assembly and use mapped struct

   withdrawalRequest = Data(slot);

   // Validate initialization

   require(withdrawalRequest.timestamp != 0, "WR_NOT_INITIALIZED");

   }
   }