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
RCE via Database Functions
OSWE · Chapter 23
RCE via Database Functions
RCE via database functions is the exploitation pattern that ties together several earlier OSWE chapters (PostgreSQL UDFs, deserialization) — using a database's own extensibility features as the mechanism to execute OS-level commands from what starts as a data-layer vulnerability.
Key concepts
- Different database engines expose different native mechanisms: PostgreSQL C-language UDFs, MSSQL `xp_cmdshell`, MySQL user-defined functions (UDFs) loaded from a plugin directory.
- This technique typically requires elevated database privileges — it is most often a post-exploitation escalation from "I have SQL injection" to "I have a shell on the DB host", not the initial foothold.
- Because it runs inside the database server process, successful exploitation compromises the entire host, not just the data the application account could normally reach.
- Hardening: disable dangerous built-in procedures (`xp_cmdshell` in MSSQL is disabled by default in modern installs), and apply least-privilege database roles so the web application account can never reach admin-only functions.
Example
-- MSSQL: classic (and heavily monitored) command execution via xp_cmdshell
EXEC xp_cmdshell 'whoami';Try it yourself
Research how `xp_cmdshell` is disabled by default in modern MSSQL installations, and explain what specific privilege an attacker would need to re-enable it via `sp_configure`.