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HTTP Header Injection

Security VulnerabilityHTTP ProtocolSQL InjectionWeb Application SecurityData Sanitization

HTTP Header Injection is a security vulnerability where attackers manipulate HTTP headers to inject malicious code, often targeting SQL databases. This occurs when headers are logged or used in SQL queries without proper sanitization.

Key Points

  • Attack Vector: Attackers exploit HTTP headers like User-Agent, Referer, or X-Forwarded-For by inserting SQL commands.
  • Vulnerability: The server processes these headers, potentially executing the injected SQL commands if not properly sanitized.
  • Impact: This vulnerability can lead to unauthorized access to sensitive data or manipulation of the database.

How It Works

Attackers manipulate HTTP headers to inject malicious SQL commands. When these headers are processed by the server, the injected commands can be executed if the headers are not properly sanitized.

Practical Example

An attacker might set the User-Agent header to ' UNION SELECT username, password FROM user; # to extract usernames and passwords from a database.

Real-World Application

Web applications that log HTTP headers or use them in database queries are at risk. For example, a web server logging user agents for analytics could be vulnerable if it stores these logs in a SQL database without proper validation.

Key Takeaways

  • Always sanitize and validate HTTP headers before using them in SQL queries.
  • Regularly review and secure logging mechanisms to prevent injection attacks.
  • Implementing prepared statements and parameterized queries can mitigate SQL injection risks.

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