Why Your API Layer Is Your Biggest Security Vulnerability

Public RPCs see every transaction you broadcast. This creates a front-running goldmine for sophisticated bots. Your users' swaps on Uniswap or Curve get sandwiched before they even reach the public mempool.\n- Front-running: Transaction order manipulation for profit.\n- Time-bandit attacks: Re-orgs to steal finalized transactions.\n- Solution: Private transaction routing via services like Flashbots Protect or dedicated RPCs.

RPC providers can silently filter or block transactions. This isn't theoretical; it's standard practice for OFAC compliance, affecting protocols like Tornado Cash. Your dApp becomes unusable for sanctioned addresses.\n- Protocol-level neutrality is bypassed.\n- Creates a centralized kill switch for your application.\n- Solution: Decentralized RPC networks or running your own infrastructure.

You trust your RPC's blockchain state. A malicious or compromised provider can feed you spoofed data, enabling theft via fake balances or incorrect pool reserves. This undermines oracle reliability and DeFi logic.\n- Fake State: Returning incorrect account balances or smart contract data.\n- Eclipse Attack: Isolating your node from the real network.\n- Solution: Multi-RPC fallbacks and cryptographic state verification.

When your public RPC goes down (see: Infura, Alchemy outages), your entire application goes down. This creates systemic risk for protocols with $10B+ TVL that depend on these services.\n- Global Downtime: Outages affect all dependent dApps simultaneously.\n- Spike-Induced Throttling: Traffic surges cause request failures.\n- Solution: Robust multi-provider architecture with automatic failover.

Every RPC request reveals user IP, wallet addresses, and behavior patterns. This data is often aggregated and sold, breaking wallet-level privacy assumptions. It deanonymizes users of zk-proof systems.\n- IP/Wallet Graph: Building comprehensive user profiles.\n- Behavioral Analytics: Tracking trading patterns and portfolio moves.\n- Solution: Privacy-preserving RPCs or using Tor/VPN gateways.

You have no enforceable Service Level Agreement (SLA) with free public RPCs. Their latency, throughput, and uptime are best-effort. For professional applications, this is operational negligence.\n- No Guarantees: On ~500ms latency or 99.9% uptime.\n- Unprioritized Requests: Your traffic competes with bots and free users.\n- Solution: Paid tier SLAs or self-hosting with defined Service Level Objectives (SLOs).

When Infura's centralized API failed due to a config error, it took down MetaMask for millions, freezing $10B+ in user assets. This wasn't a smart contract hack; it was a trusted web2 dependency failing.

• Single Point of Failure: One provider outage = global app failure.
• Censorship Vector: Providers can theoretically block transactions to specific contracts or addresses.
• Data Integrity Risk: A compromised RPC can return spoofed blockchain data, enabling front-running and MEV attacks.

Solana's reliance on a handful of Jito and Triton RPC providers created a de facto MEV cartel. Validators running these services could see and reorder transactions before they hit the public mempool.

• Centralized MEV Extraction: A few entities control transaction flow, extracting value from users.
• Performance Monopoly: Apps are forced to use these "fast lane" RPCs to remain competitive, cementing their power.
• Trust Assumption: Users must trust these providers not to censor or exploit their transactions.

While not a traditional API, Chainlink operates as trusted data infrastructure. If its nodes are compromised or collude, they can front-run price updates. The bZx flash loan attack exploited a similar oracle manipulation vector for $8M.

• Data Manipulation: A corrupted price feed can drain lending protocols and AMMs in seconds.
• Centralized Relay Network: Data flows through a permissioned set of nodes, a high-value target.
• Systemic Risk: A single oracle failure can cascade across hundreds of integrated DeFi protocols.

Alchemy and Moralis dominate the web3 backend-as-a-service market, creating a data monoculture. Their indexed data is treated as canonical, but bugs or malicious updates in their indexing logic can poison every downstream application.

• Indexing is Opinionated: Providers decide what data to index and how, which can omit or misrepresent on-chain state.
• Vendor Lock-in: Proprietary APIs make switching providers costly and slow, reducing resilience.
• Silent Failures: An incorrect balance or NFT ownership query can break app logic without an obvious blockchain reorg.