Blog
Field notes for people shipping Rust and Anchor programs — the vulnerability classes that actually drain vaults, why they happen, and the constraints that stop them. Every post has vulnerable code next to the fix. Alongside them, essays on floor — the fewest signatures that could change the code under a DeFi position, and why audits don't measure it.
An audit says whether the code was correct on the day it was reviewed. Floor counts the fewest signatures that could change it now — across upgrade authority, oracles and governance.
Signer rotations, governance token accumulation and oracle reconfigurations each look routine. Together they can take a protocol from floor 3 to floor 1 without a single announcement.
DORA requires a register of ICT third-party arrangements but says nothing about a DeFi protocol with no contract. What a usable entry needs — upgrade authority, oracles, floor — and a practical format for it.
DeFi position risk is a counterparty question, not a security one. How floor feeds position sizing, concentration limits and hedge triggers — the way a CDS spread does for credit.
A seven-step review pass over an Anchor codebase — instruction authority, the escape hatches that disable Anchor's automatic checks, account constraints, CPIs, arithmetic and account lifecycle — ending in a checklist you can paste into your review notes.
The eight mistakes behind most Solana exploits — missing signer and owner checks, type cosplay, PDA seed and bump errors, arbitrary CPIs, integer overflow, duplicate mutable accounts and account revival — each with vulnerable and fixed Anchor code.
In the works
Solana vs Ethereum Smart Contract Security: What's Actually Different
Why an EVM security checklist won't protect a Solana program.
Missing Signer and Owner Checks: The Solana Bug That Drains Vaults
A deep dive into the two most expensive Solana vulnerabilities, with real attack scenarios.
Solana PDA Security: Seeds, Bumps, and the Mistakes That Bite
Non-canonical bumps, unvalidated seeds and unsafe signing — with Anchor fixes.
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