Courses
1. Introduction to Blockchain and Solana
2. Setting Up Your Development Environment
3. Solana Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Solana Programs
6. Building Your First Solana Program
7. Deploying Programs on the Solana Network
8. Interacting with Solana Programs
9. Using Solana CLI and SDKs
10. Developing Decentralized Applications (DApps)
11. Smart Contract Security Best Practices
12. Testing and Debugging Solana Programs
13. Optimizing Performance on Solana
14. Exploring Solana Ecosystem Tools
1. Introduction to Blockchain and Ethereum
2. Setting Up Your Development Environment
3. Ethereum Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Smart Contracts
6. Building Your First Smart Contract
7. Deploying Smart Contracts on the Ethereum Network
8. Interacting with Smart Contracts
9. Using Ethereum CLI and SDKs
10. Developing Decentralized Applications (DApps)
11. Smart Contract Security Best Practices
12. Testing and Debugging Smart Contracts
13. Optimizing Performance on Ethereum
14. Exploring Ethereum Ecosystem Tools
1. Introduction to Blockchain and Polygon
2. Setting Up Your Development Environment
3. Polygon Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Smart Contracts on Polygon
6. Building Your First Smart Contract on Polygon
7. Deploying Smart Contracts on the Polygon Network
8. Interacting with Smart Contracts on Polygon
9. Using Polygon CLI and SDKs
10. Developing Decentralized Applications (DApps) on Polygon
11. Smart Contract Security Best Practices for Polygon
12. Testing and Debugging Smart Contracts on Polygon
13. Optimizing Performance on Polygon
14. Exploring Polygon Ecosystem Tools
1. Introduction to Cybersecurity
2. Report Writing for Penetration Testers
3. Information Gathering
4. Vulnerability Scanning
5. Introduction to Web Applications
6. Common Web Application Attacks
7. SQL Injection Attacks
8. Client-Side Attacks
9. Locating Public Exploits
10. Fixing Exploits
11. Antivirus Evasion
12. Password Attacks
13. Windows Privilege Escalation
14. Linux Privilege Escalation
15. Advanced Tunneling
16. The Metasploit Framework
17. Active Directory: Introduction and Enumeration
18. Attacking Active Directory Authentication
19. Lateral Movement in Active Directory
Magic Hashes
OSWE · Chapter 15
Magic Hashes
"Magic hashes" are a specific PHP loose-comparison bug (covered conceptually in the Type Juggling chapter) where certain hash strings that begin with "0e" followed by only digits are interpreted as scientific-notation zero, letting two completely different hash values compare as equal.
Key concepts
- Any hash function whose output can coincidentally start with `0e` followed by digits only is vulnerable if compared with `==` rather than `===`.
- This mainly matters for password/token verification code, where an attacker who can influence one side of the comparison (e.g. supply a "magic" input) can forge a match without knowing the real secret.
- MD5 and SHA-1 have both been used historically in magic-hash proof-of-concepts because their hex output occasionally happens to start with "0e".
- The fix from the previous chapter applies directly: always use `===` (or a constant-time comparison function) for any security-sensitive string comparison.
Example
<?php
// Two different inputs whose MD5 both happen to look like "0e..." numbers
var_dump(md5("240610708") == md5("QNKCDZO")); // true in loose comparisonTry it yourself
Look up two known "magic hash" MD5 collision strings and verify with `var_dump(... == ...)` in a local PHP sandbox that they compare equal under loose comparison but not under `===`.