Scans Algorand smart contracts for 11 common vulnerabilities including rekeying attacks, unchecked transaction fees, missing field validations, and access control issues. Use when auditing Algorand projects (TEAL/PyTeal).
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Scans Algorand smart contracts for 11 common vulnerabilities including rekeying attacks, unchecked transaction fees, missing field validations, and access control issues. Use when auditing Algorand projects (TEAL/PyTeal).
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Stars6,227
Forks540
LanguagePython
LicenseCC-BY-SA-4.0
📦 Ships with trailofbits-skills
</> SKILL.md
algorand-vulnerability-scanner.SKILL.md
---name: algorand-vulnerability-scanner
description: Scans Algorand smart contracts for 11 common vulnerabilities including rekeying attacks, unchecked transaction fees, missing field validations, and access control issues. Use when auditing Algorand projects (TEAL/PyTeal).
---# Algorand Vulnerability Scanner
## 1. Purpose
Systematically scan Algorand smart contracts (TEAL and PyTeal) for platform-specific security vulnerabilities documented in Trail of Bits' "Not So Smart Contracts" database. This skill encodes 11 critical vulnerability patterns unique to Algorand's transaction model.
## 2. When to Use This Skill
- Auditing Algorand smart contracts (stateful applications or smart signatures)
- Reviewing TEAL assembly or PyTeal code
- Pre-audit security assessment of Algorand projects
- Validating fixes for reported Algorand vulnerabilities
- Training team on Algorand-specific security patterns
## 3. Platform Detection
### File Extensions & Indicators
- **TEAL files**: `.teal`
- **PyTeal files**: `.py` with PyTeal imports
### Language/Framework Markers
```python
# PyTeal indicators
from pyteal import *
from algosdk import *
# Common patterns
Issue: The contract doesn't validate the RekeyTo field, allowing attackers
to change account authorization and bypass restrictions.
---
## 5. Vulnerability Patterns (11 Patterns)
I check for 11 critical vulnerability patterns unique to Algorand. For detailed detection patterns, code examples, mitigations, and testing strategies, see [VULNERABILITY_PATTERNS.md](resources/VULNERABILITY_PATTERNS.md).
### Pattern Summary:
1. **Rekeying Vulnerability** ⚠️ CRITICAL - Unchecked RekeyTo field
2. **Missing Transaction Verification** ⚠️ CRITICAL - No GroupSize/GroupIndex checks
3. **Group Transaction Manipulation** ⚠️ HIGH - Unsafe group transaction handling
4. Verify OnComplete fields for ApplicationCalls in group
### Step 6: Access Control Review
- [ ] Creator/admin privileges properly enforced
- [ ] Update/delete operations protected
- [ ] Sensitive functions have authorization checks
---
## 6. Reporting Format
### Finding Template
```markdown
## [SEVERITY] Vulnerability Name (e.g., Missing RekeyTo Validation)
**Location**: `contract.teal:45-50` or `approval_program.py:withdraw()`
**Description**:
The contract approves payment transactions without validating the RekeyTo field, allowing an attacker to rekey the account and bypass future authorization checks.
**Vulnerable Code**:
```python
# approval_program.py, line 45
If(Txn.type_enum() == TxnType.Payment,
Approve() # Missing RekeyTo check
)
```
**Attack Scenario**:
1. Attacker submits payment transaction with RekeyTo set to attacker's address
2. Contract approves transaction without checking RekeyTo
