Signature Detail

HTTP: SQL 'declare...exec' Command Injection in URL

This signature detects SQL commands within a URL. Because SQL commands are not normally used in HTTP connections, this can indicate a SQL injection attack. However, it can be a false positive. To reduce false positives, it is strongly recommended that these signatures only be used to inspect traffic from the Internet to your organization's web servers that use SQL backend databases to generate content and not to inspect traffic going from your organization to the Internet. This particular technique involves encoding an attack inside a SQL variable using DECLARE and then running the attack using an EXEC on the variable. This attack is being used by botnets to evade SQL injection protection.

Extended Description

By manipulating SQL queries in the URL, a malicious user is able to guide the execution flow of a SQL server to cause unexpected operations in the SQL backend. This results in data leaks, or false authentications.

References

• URL: http://isc.sans.org/diary.html?storyid=3823
• URL: http://isc.sans.edu/diary/SQL+Injection+Attack+happening+ATM/12127