Rappie
Fuzzing specialist. ASR at Spearbit. CTO of Perimeter guild.
@Rappie
asr
Biography
About Me
I'm Rappie, CTO & Lead Fuzzing Specialist at Perimeter, Associate Security Researcher at Spearbit, and active in bug bounty on Immunefi. I specialize in fuzzing EVM-based smart contracts to help protocols secure their code.
Beyond security research and protocol assessments, I contribute to the fuzzing community through open-source projects like EVM Fuzzing Resources and the List of Public Fuzzing Campaigns.
Testimonials
Rappie found some extremely subtle behaviors in our code that many others missed. He not only uses the cutting edge of multiple fuzzing engines, but also helps shape how these fuzzers are built. We've been delighted to use his mastery to make our contracts more secure.
Rappie went above and beyond to deeply understand our protocol and cover all the edge cases. His experience and knowledge about the art of fuzzing is unparalleled. Overall he is an incredible security expert, we certainly will be returning to him with our future smart contracts.
Security & Fuzzing Engagements
| Protocol | Engagement Type | Completed | Report | Code |
|---|---|---|---|---|
| Origin Protocol | Perimeter Fuzzing Engagement | 2025-03 | ||
| Berachain | Perimeter Fuzzing Engagement | 2025-01 | ||
| Berachain | Perimeter Fuzzing Engagement | 2024-12 | ||
| Berachain | Perimeter Fuzzing Engagement | 2024-12 | ||
| Berachain | Perimeter Fuzzing Engagement | 2024-11 | ||
| Berachain | Perimeter Fuzzing Engagement | 2024-10 | ||
| Berachain | Perimeter Fuzzing Engagement | 2024-09 | ||
| Berachain | Fuzzing Specialist during Spearbit Security Review | 2024-08 | ||
| Private | Fuzzing Specialist during Spearbit Security Review | 2024-05 | ||
| Origin Protocol | Perimeter Fuzzing Engagement | 2024-05 | Report | Code |
| Private | Perimeter Fuzzing Engagement | 2024-04 | ||
| Coinbase | Fuzzing Specialist during Spearbit Security Review | 2024-03 | Report | |
| Coinbase | Fuzzing Specialist during Spearbit Security Review | 2024-03 | Report | |
| Drips Network | Perimeter Fuzzing Engagement | 2024-01 | Code | |
| Drips Network | Fuzzing Specialist during Spearbit Security Review | 2023-11 | Report | |
| Private | Perimeter Fuzzing Engagement | 2023-11 | ||
| Origin Protocol | Fuzzing Engagement | 2023-09 | Code | |
| Origin Protocol | Fuzzing & Audit | 2023-03 | Report |
Open Source Contributions
| Project | Link |
|---|---|
| EVM Fuzzing Resources | Link |
| List of Public Fuzzing Campaigns | Link |
| Creator of Fuzzlib, a General Purpose Unopinionated Solidity Fuzzing Library | Link |
| Reproduction of the Rari Finance hack using on-chain fuzzing with Echidna | Link |
| Reproduction of the Curve Reentrancy hacks using on-chain fuzzing with Echidna | Link |
| Author of Echidna Exercise: Solve Damn Vulnerable DeFi - Side Entrance | Exercise, PR |
Bug Bounties & Competitions
| Description | Severity | Report | Platform | Protocol |
|---|---|---|---|---|
Incorrect argument passed to Utils.characterToUnicodeBytes in Namespace.fuse | High | Report | Code4rena | Canto Identity |
Calling OUSD.burn() on an address with zero balance causes the totalSupply to go down | Low | Report | Immunefi | Origin Protocol |
Vault.redeem() fails with only non-rebasing credits in the protocol | Low | Report | Immunefi | Origin Protocol |
| Total supply can become larger than max supply | Low | Report | Immunefi | Origin Protocol |
LiquidityTree.push() does not always update state correctly | Low | Report | Immunefi | Azuro |
OUSD.burn() allows for destroying supply while balance remains | Low | Report | Immunefi | Origin Protocol |
Get in Touch
I'm open to fuzzing engagements, security research, consulting, and general fuzzing-related questions. Feel free to reach out!
- X: @rappie_eth
- Discord:
rappie - Telegram:
@rappenstein - Cantina: Rappie
Private reviews
View allSecurity portfolio
Title | Description |
|---|---|
| OETHVault Fuzzing Report | Report for the Origin Protocol OETHVault fuzzing campaign |
| OETHVault Fuzzing Campaign | Fuzzing campaign for the Origin Protocol OETHVault |
| Drips Fuzzing Campaign | Fuzzing Campaign and Spearbit Security Review for Drips Network |
| Reproducing Rari Finance Hack | Reproduction of the Rari Finance hack using Echidna |
| OUSD Fuzzing Campaign | Fuzzing campaign for the Origin Protocol OUSD token |