attack-surface.md

Attack Surface Analysis for jetbrains/exposed

Attack Surface: SQL Injection via Dynamic SQL Construction

• Description: Attackers can inject malicious SQL code by exploiting dynamic SQL query construction, leading to unauthorized database access and manipulation.
• How Exposed Contributes: Exposed allows dynamic SQL construction through string interpolation within DSL functions like CustomFunction and via raw SQL queries using exec(). This flexibility, if misused, directly enables SQL injection vulnerabilities.
• Example:

  fun findUserById(userId: String) {
      val query = "SELECT * FROM Users WHERE id = '$userId'" // Vulnerable!
      transaction {
          exec(query) { rs -> /* ... */ }
      }
  }
  // An attacker could call findUserById("1 OR 1=1; --") to bypass ID check.

• Impact: Data breach, data modification, data deletion, denial of service, privilege escalation, potentially full database compromise.
• Risk Severity: Critical
• Mitigation Strategies:
  • Strictly use parameterized queries: Leverage Exposed's DSL for parameterized queries, avoiding string interpolation for user-provided data.
  • Minimize raw SQL usage: Prefer Exposed's DSL over exec() for query construction to benefit from built-in safety mechanisms. If raw SQL is necessary, parameterize it meticulously.
  • Input validation and sanitization (defense-in-depth): Validate and sanitize user input even when using parameterized queries as a secondary security layer.

Attack Surface: SQL Injection via Insecure Custom SQL Fragments

• Description: Developers creating reusable custom SQL fragments or functions within Exposed can introduce SQL injection vulnerabilities if these fragments are not properly parameterized and handle user input unsafely.
• How Exposed Contributes: Exposed's extensibility allows defining custom SQL functions and fragments. If these custom components are built using string concatenation or other insecure practices, they become injection points within Exposed queries.
• Example:

  // Insecure custom function
  fun unsafeOrderBy(columnName: String): CustomFunction<String> = 
      CustomFunction<String>("ORDER BY ?", StringColumnType(), arrayOf(StringLiteral(columnName))) // Vulnerable!
  
  fun getUsersOrderedBy(column: String) {
      Users.selectAll().orderBy(unsafeOrderBy(column)) // Vulnerable usage
  }
  // Attacker could call getUsersOrderedBy("name; DROP TABLE Users; --")

• Impact: Data breach, data modification, data deletion, denial of service, privilege escalation, potentially full database compromise.
• Risk Severity: Critical
• Mitigation Strategies:
  • Parameterize custom SQL components: Ensure all custom SQL fragments and functions accept parameters and utilize placeholders (?) for dynamic values, preventing direct string interpolation of user input.
  • Thoroughly review custom SQL code: Conduct rigorous security reviews and testing of all custom SQL code for potential injection flaws before deployment.
  • Prefer DSL features over custom SQL: Utilize Exposed's built-in DSL features as much as possible to minimize the need for custom SQL and reduce the risk of introducing vulnerabilities.

Attack Surface: Vulnerabilities in Exposed Library Itself

• Description: Security vulnerabilities may be discovered within the Exposed library code itself, potentially allowing attackers to exploit weaknesses in the ORM framework.
• How Exposed Contributes: As a software library, Exposed is susceptible to vulnerabilities. Using outdated or vulnerable versions of Exposed directly exposes applications to these risks.
• Example: A hypothetical vulnerability in Exposed's query parsing or execution logic that could be triggered by specially crafted input, leading to unauthorized actions or denial of service.
• Impact: Application compromise, data breach, denial of service, depending on the nature and severity of the vulnerability.
• Risk Severity: High to Critical (depending on the specific vulnerability discovered)
• Mitigation Strategies:
  • Keep Exposed updated: Regularly update to the latest stable version of the Exposed library to benefit from security patches and bug fixes.
  • Monitor security advisories: Stay informed about security advisories and vulnerability reports related to JetBrains Exposed.
  • Dependency scanning: Employ dependency scanning tools to automatically detect known vulnerabilities in the Exposed library and its dependencies.

Attack Surface: Vulnerabilities in Database Driver Dependencies

• Description: JDBC drivers, which Exposed relies on to interact with databases, can contain security vulnerabilities that could be exploited through the Exposed application.
• How Exposed Contributes: Exposed depends on JDBC drivers for database connectivity. Vulnerabilities in these drivers indirectly impact Exposed applications, as they are the underlying mechanism for database interaction.
• Example: A vulnerability in a specific PostgreSQL JDBC driver that allows for remote code execution when processing certain database responses. An Exposed application using this driver would be vulnerable.
• Impact: Application compromise, data breach, denial of service, potentially remote code execution on the database server or application server, depending on the driver vulnerability.
• Risk Severity: High to Critical (depending on the specific driver vulnerability)
• Mitigation Strategies:
  • Keep JDBC drivers updated: Regularly update JDBC drivers to the latest versions provided by database vendors to patch known security vulnerabilities.
  • Monitor driver security advisories: Subscribe to security advisories and vulnerability databases for the specific JDBC drivers used in your application.
  • Dependency scanning: Include JDBC drivers in your dependency scanning process to identify and address vulnerable driver versions.

Attack Surface: Insecure Schema Migration Processes (If using Exposed for Schema Management)

• Description: If Exposed is used for database schema migrations, poorly written or insecure migration scripts can introduce vulnerabilities during database schema updates.
• How Exposed Contributes: Exposed provides features for schema management and migrations. If these features are used to execute migration scripts that contain insecure SQL or logic, they can directly introduce vulnerabilities into the database schema.
• Example: A migration script that creates a new table but inadvertently grants overly permissive access rights to public users, or a script that introduces a stored procedure with an SQL injection vulnerability.
• Impact: Introduction of persistent vulnerabilities into the database schema, potentially leading to data breaches, privilege escalation, or data corruption.
• Risk Severity: High
• Mitigation Strategies:
  • Secure migration script development: Treat migration scripts as critical code and apply secure coding practices. Review and test migration scripts thoroughly before execution.
  • Principle of least privilege in migrations: Ensure migration scripts only grant necessary permissions and follow the principle of least privilege when creating users or roles.
  • Automated and version-controlled migrations: Implement automated and version-controlled migration processes to ensure consistency and auditability.
  • Separate migration user: Use a dedicated database user with limited privileges specifically for running migrations, reducing the impact if migration credentials are compromised.