There’s a reality most blockchain developers learn the hard way: Rust’s memory safety won’t save your system. I know that sounds counterintuitive.
You learned Rust because it’s safe and an excellent language for blockchain development. Its memory safety guarantees eliminate entire classes of vulnerabilities that plague other systems programming languages. It eliminates entire classes of bugs that plague C and C++. That part is true.
But in blockchain development, mistakes in ownership and account design can lead to critical vulnerabilities: asset loss, program failure, or exploits. The core issues stem from misunderstanding Rust's memory safety rules and failing to validate on-chain account data properly.
However, the ecosystem has seen over $1B in exploits, and the meaningful failures weren’t memory bugs. There were logic errors: missing validation checks, broken authority verification, and incorrect assumptions about derived accounts.
▲ So let me show you the 8 fatal mistakes that actually break programs in production and how to mitigate them.
▲ 1. Missing Account Ownership & Collateral Validation
The most common failure I see in Rust-based blockchain programs. In March 2022, Cashio lost $52M when an attacker bypassed collateral checks, deposited worthless LP tokens into a fake bank, and minted unlimited tokens. The program never verified the collateral or the bank.
This wasn’t a Rust memory bug; it was a protocol logic flaw.
Key takeaways:
Always verify token accounts match the expected mint.
Confirm accounts are owned by the correct program.
Treat every account as potentially malicious.
▲ 2. Price Oracle & Token Valuation Failures
Even in 2025, Rust-based blockchain protocols get exploited from logic flaws, not memory bugs. The Loopscale protocol lost $5.8M when it miscalculated the value of derivative tokens. The program didn’t verify price oracles, token-specific valuation logic, or account correctness.
Lessons:
Always validate that oracles are correct and resistant to manipulation.
Implement token-specific valuation logic for derivatives.
Use safety margins when calculating collateral.
Test economic assumptions under real-world conditions.
Rust’s memory safety can’t protect you from these; this is purely business logic and validation risk.
▲ 3. Stale Data After External Calls.
When an external program call is made that modifies an account being read in the current instruction, the in-memory copy of the data is not automatically updated. You read the balance, make a call that transfers assets, then read the balance again but you’re looking at a snapshot from when the instruction started.
Calculations on stale data lead to incorrect and potentially exploitable behavior. Explicitly reload account data after every external call that might modify accounts you’re still working with.
▲ 4. Arbitrary External Calls / Privilege Escalation
This is basically the blockchain equivalent of SQL injection.
You’re letting user input determine program execution. The attacker passes in their own malicious program instead of the real one. You call it with your program’s signing authority. Now they can do whatever they want with accounts your program controls: drain funds, manipulate state, whatever.
Always verify the program ID before making external calls.
▲ 5. Derived Address Manipulation
Multiple valid derivations can exist for the same seeds. If you don’t enforce the canonical derivation, attackers can create alternate addresses that pass your checks but point to different accounts.
That’s how you end up with:
Multiple vaults for the same user.
Replayed claims.
Bypassed limits
Always derive addresses canonically and store the canonical derivation at creation time.
▲ 6. Missing Signer Authorization.
This gets overlooked constantly. I still see instructions that mutate admin state with no signer checks. Anyone can call them. Using a signer only proves the transaction was signed.
You still need to verify that the signer has the **correct authority **for the operation.
Signed ≠ authorized.
▲ 7. Integer Overflow in Release Mode.
In debug mode, Rust panics on overflow. In release mode which is what production runs it silently wraps.
Balance is 100. Someone withdraws 200. Instead of failing, the value wraps to a huge number.
Always use checked arithmetic:
checked_add, checked_sub, checked_mul.
For financial logic, use fixed-point math. Floating point is not an option.
▲ 8. Zero-Copy and Unsafe Rust
When you’re dealing with large accounts and hit stack or heap limits, you reach for zero-copy. It’s powerful but dangerous. Zero-copy uses packed representations, making field references unsafe. When fields are packed, they’re not aligned in memory the way Rust expects. Creating a reference to an unaligned field is undefined behavior.
Copy the value instead of taking a reference. Don’t reach for zero-copy unless necessary; only use it for extremely large accounts that can’t be safely deserialized.
▲ Here’s the mental model you need to internalize when carrying out a transfer function:
Does this account need to sign, and was it authorized?.
Who owns each account, and what is the response I expect?.
Does this token account belong to the expected mint?
Is the data initialized and in the correct state?.
If I’m calling another logic, is it the correct one?.
Did I reload accounts after external calls that have been mutated?.
Am I using checked arithmetic everywhere?
▲ Trust nothing. Verify everything.
Don’t rely solely on Rust’s compiler guarantees.
Invest in thorough testing, code reviews, and professional security audits.
Before launch, audit for privilege escalation, authority validation, unsafe Rust, and logic flaws.
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