Bridges have produced some of the largest exploits in crypto history, because a single validation bug doesn't just expose one protocol's TVL — it exposes every integrator that trusts the bridge's message-validation predicate. Firepan's private review of VIA Labs' cross-chain gateway is a direct example: two confirmed auth-bypass primitives in the function that validates every message crossing the network. Read the full report.
Bridge validation logic is predicate-heavy — a handful of functions carry the entire trust boundary of the system, and the bugs that matter are usually a missing check in that predicate rather than a broad class of pattern. Firepan's methodology walks the registration-to-validation path for every signer property: if a property is written at registration (a signer's scope, its enabled state, its layer), does the validation predicate actually re-assert that property before counting the signature? That's precisely the class of bug — a scope check and an enabled-state check both missing from the same function — that Firepan's HOUND AI engine surfaced in the VIA Labs engagement.
Static analysis and fuzzing catch a meaningful share of bridge issues, but predicate-level enumeration against the specific signer/registration model is where a bridge audit earns its cost. Firepan combines automated tooling with this kind of targeted, architecture-aware review for cross-chain codebases.
Q: Why are bridge exploits so much larger than typical DeFi exploits?
A: A bridge's trust boundary extends to every project that integrates it, not just the bridge's own funds. A single validation bug can expose the combined TVL of every integrating protocol simultaneously — which is why bridge exploits have produced some of the largest losses in crypto history.
Q: What's the most common bridge vulnerability class?
A: Missing scope or state checks in the message-validation predicate — for example, a signature-counting function that doesn't verify a signer is scoped to the right recipient, or doesn't check whether a signer has been disabled. Firepan's VIA Labs engagement found exactly this pattern: two separate missing checks in the same validation function.
Q: Can automated tools alone catch bridge vulnerabilities?
A: Automated static analysis and fuzzing catch a real share of issues, but the highest-value bridge bugs are typically predicate-level logic gaps — a specific property that's set in one function and never re-checked in another. That requires walking the registration-to-validation path deliberately, which is where Firepan's HOUND AI-driven review adds the most value beyond raw tooling.
Q: Does Firepan monitor bridges after deployment?
A: Firepan does not claim blanket on-chain monitoring of deployed bridges. Connected repository events can trigger new code analysis, but teams must separately monitor signer sets, thresholds, relayer permissions, governance actions, and live transactions.
Read the VIA Labs case study or run a free surface scan on your bridge contracts now.
Firepan
Run a free surface scan — results in minutes, no credit card required.
Run Free Scan →