Algo Ssstablecoinsss
AI First Flight #2
Beginner FriendlyDeFi
EXP
View results
Previous Next
Submission Details
Impact: low
Likelihood: low
Invalid

L02 Missing constructor validation for critical addresses

adcdiii

Root + Impact

Description

  • Normal behavior: The constructor of the engine should validate all critical addresses (tokens, price feeds, DSC token) to ensure they are non‑zero and non‑duplicate, preventing deployment misconfiguration.

  • Issue: The current constructor does not validate these inputs; zero addresses or duplicates can be passed without reverting, leading to permanently broken mappings and collateral accounting.

// dsc_engine.vy (conceptual)
@external
def __init__(token_addresses: address[2], price_feeds: address[2], dsc_address: address):
self.token_addresses = token_addresses
self.price_feeds = price_feeds
self.dsc_address = dsc_address
# @> no checks for zero or duplicate addresses

Risk

Likelihood:

  • Reason 1 // Deployment scripts and environment variables are error‑prone; a single mis‑typed address or copy‑paste error is common.

  • Reason 2 // Multi‑environment setups (testnets, staging, mainnet) increase the chance of inconsistent or invalid configuration.

Impact:

  • Impact 1 // Zero addresses for tokens or feeds can cause runtime reverts and unfixable behavior in production, requiring a full redeploy and migration.

  • Impact 2 // Duplicate token addresses or feed mappings can lead to double‑counting or mis‑routing collateral value, silently breaking risk assumptions.

Proof of Concept

A misconfigured deployment passes a zero address as a collateral token:

  1. Deployer invokes the constructor with token_addresses[0] = 0x0.

  2. Contract deploys successfully without validation.

  3. Any attempt to deposit or value that collateral will either revert or behave unpredictably.

  4. Since the constructor cannot be called again, the only remedy is a full redeploy.

function testZeroAddressInConstructorLeadsToBrokenProtocol() public {
address[2] memory tokens = [address(0), address(weth)];
address[2] memory feeds = [address(priceFeed1), address(priceFeed2)];
​
// @> currently, this does not revert, deploying a broken engine
DSCEngine engine = new DSCEngine(tokens, feeds, address(dsc));
}

Recommended Mitigation

Add explicit assertions to the constructor for non‑zero and non‑duplicate addresses.

@external
def __init__(token_addresses: address[2], price_feeds: address[2], dsc_address: address):
+ assert token_addresses[0] != empty(address), "DSCEngine__ZeroAddress"
+ assert token_addresses[1] != empty(address), "DSCEngine__ZeroAddress"
+ assert token_addresses[0] != token_addresses[1], "DSCEngine__DuplicateToken"
+ assert dsc_address != empty(address), "DSCEngine__ZeroAddress"
self.token_addresses = token_addresses
self.price_feeds = price_feeds
self.dsc_address = dsc_address
Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge 10 days ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

Support

FAQs

Can't find an answer? Chat with us on Discord, Twitter or Linkedin.

Give us feedback!