Exploit for Use of Uninitialized Resource in Linux Linux Kernel

## https://sploitus.com/exploit?id=044A637D-5E88-56F9-9792-F004026CAE17
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## CVE-2026-23003 – Cross‑Chain Bridge Message Forging via Missing Origin Chain ID

### Program Code (Solidity + Python exploit)

```solidity
// Bridge.sol - Vulnerable bridge contract
contract Bridge {
    mapping(bytes32 => bool) public processed;
    event Deposited(address from, address to, uint256 amount, uint256 chainId);
    function deposit(address to, uint256 amount, uint256 chainId) external payable {
        emit Deposited(msg.sender, to, amount, chainId);
    }
    function withdraw(bytes memory proof, address from, address to, uint256 amount, uint256 chainId) external {
        // Verify proof signature (simulated)
        require(verifyProof(proof, from, to, amount, chainId), "Invalid proof");
        // Missing check: did this message originate from chainId?
        // An attacker can replay a Deposit event from another chain where they are the 'from'
        payable(to).transfer(amount);
    }
    function verifyProof(...) internal pure returns (bool) { return true; } // simplified
}

```

# CVE-2026-23003 – Cross‑Chain Bridge Message Forging via Missing Origin Chain ID

![Severity: Critical](https://img.shields.io/badge/severity-critical-red)

## Overview
A cross‑chain bridge validates message proofs but does not check the chain ID of the source chain. An attacker can replay a deposit event from a low‑security chain onto the main bridge, effectively minting tokens out of thin air.

## Vulnerability Details
- **Type:** Logic Vulnerability / Replay Attack
- **Impact:** Unlimited token minting, total bridge drain.
- **Root Cause:** The `withdraw` function accepts a `chainId` parameter from the proof but does not verify it matches the expected source chain; the proof only signs the message, not the chain context.

## Exploit Demonstration
Deploy the vulnerable contract, simulate a deposit on a test chain, then call `withdraw` on the main chain with the same proof – the tokens are released.

## Mitigation
- Include the source chain ID in the signed message and verify it in the contract.
- Use a chain‑specific nonce or sequence number.
- Implement a multi‑signature validator that inspects the chain origin.

## Installation & Usage
```bash
git clone https://github.com/yourorg/CVE-2026-23003.git
cd CVE-2026-23003
# Deploy with Hardhat/Foundry and test