attack-surface.md

Attack Surface Analysis for ccgus/fmdb

Attack Surface: SQL Injection

• Description: Attackers exploit vulnerabilities in application code that uses fmdb to construct SQL queries by injecting malicious SQL code. This manipulates the intended query logic executed by fmdb against the SQLite database.
• How fmdb Contributes: fmdb provides methods to execute SQL queries. If developers use string formatting or concatenation to build these queries with unsanitized user input before passing them to fmdb's execution methods, fmdb becomes the tool that executes the injected malicious SQL. fmdb itself doesn't introduce the injection vulnerability, but insecure usage patterns with fmdb directly enable it.
• Example: An application uses fmdb to execute a query built like: NSString *sql = [NSString stringWithFormat:@"SELECT * FROM items WHERE name = '%@'", userInput]; [db executeQuery:sql];. If userInput is crafted as ' OR '1'='1' --, fmdb will execute SELECT * FROM items WHERE name = '' OR '1'='1' --', bypassing the intended filtering and potentially exposing all items.
• Impact: Data breach (reading sensitive data), data modification, data deletion, authentication bypass, privilege escalation, denial of service.
• Risk Severity: Critical to High
• Mitigation Strategies:
  • Strictly Use Parameterized Queries with fmdb: Always utilize fmdb's parameterized query methods (e.g., executeQuery:withArgumentsInArray:, executeUpdate:withArgumentsInArray:) and pass user inputs as arguments using ? placeholders. This ensures fmdb treats user input as data, not executable SQL code.
  • Input Validation and Sanitization (Defense in Depth): While parameterization is the primary defense, still validate and sanitize user input before even passing it to fmdb as arguments. This provides an extra layer of protection against unexpected data or encoding issues.

Attack Surface: SQLite Vulnerabilities (Exposed via fmdb)

• Description: fmdb relies on the underlying SQLite library. Critical vulnerabilities within the specific SQLite version linked with fmdb can be exploited through application interactions facilitated by fmdb. Attackers can craft inputs or trigger application flows that cause fmdb to interact with SQLite in a way that exposes these underlying SQLite vulnerabilities.
• How fmdb Contributes: fmdb acts as the interface to SQLite. If the linked SQLite library has vulnerabilities, any operation performed through fmdb that triggers the vulnerable code path in SQLite becomes an attack vector. fmdb doesn't create the SQLite vulnerabilities, but it provides the means for the application to interact with the vulnerable SQLite code.
• Example: A known remote code execution vulnerability exists in a specific older version of SQLite related to handling of certain SQL functions. If an application using fmdb and this vulnerable SQLite version processes user-provided SQL (even indirectly through application logic), an attacker could craft input that, when processed by fmdb and passed to SQLite, triggers the vulnerable function and allows remote code execution.
• Impact: Remote code execution, denial of service, data corruption, information disclosure, potentially full system compromise depending on the SQLite vulnerability.
• Risk Severity: High to Critical
• Mitigation Strategies:
  • Maintain Up-to-Date SQLite via fmdb Dependencies: Ensure the fmdb dependency in your project is configured to use the latest stable and patched version of SQLite. Regularly update dependencies and monitor for security advisories related to SQLite.
  • Dependency Management and Auditing: Use robust dependency management tools to track and manage fmdb and its SQLite dependency. Regularly audit dependencies for known vulnerabilities.
  • Consider Static Analysis and Fuzzing (Advanced): For high-security applications, employ static analysis and fuzzing techniques to analyze application code and its interaction with fmdb and SQLite to proactively identify potential vulnerability triggers before they are exploited.

Attack Surface: Denial of Service through Resource Exhaustion (via fmdb Query Execution)

• Description: Attackers can craft or trigger execution of highly resource-intensive SQL queries through fmdb. By sending a flood of these malicious queries or exploiting application logic to generate them, attackers can exhaust database server or device resources, leading to denial of service.
• How fmdb Contributes: fmdb is the mechanism through which the application executes SQL queries. Maliciously crafted or inefficient queries, when executed via fmdb, directly consume database resources (CPU, memory, I/O). fmdb is the tool that enables the execution of these resource-exhausting queries.
• Example: An attacker identifies an endpoint in the application that, when triggered, causes fmdb to execute a complex SQL query with multiple joins and aggregations based on user-controlled parameters. By sending numerous requests to this endpoint with parameters designed to maximize query complexity, the attacker can overload the database, making the application unresponsive to legitimate users.
• Impact: Application unavailability, slow performance, server/device crashes, impacting legitimate users.
• Risk Severity: Medium to High (High when easily exploitable and significantly impacts availability).
• Mitigation Strategies:
  • Optimize SQL Queries Executed by fmdb: Carefully design and optimize all SQL queries executed by fmdb. Use indexes, avoid unnecessary complexity, and profile queries to identify and eliminate performance bottlenecks.
  • Implement Rate Limiting and Throttling on Application Endpoints: Implement rate limiting and throttling on application endpoints that trigger database queries via fmdb. This restricts the number of requests from a single source, mitigating flood-based DoS attacks.
  • Resource Monitoring and Alerting: Monitor database resource usage (CPU, memory, disk I/O) in real-time. Set up alerts to detect unusual spikes in resource consumption that might indicate a DoS attack.
  • Query Timeout Limits (Application Level): Implement application-level timeout limits for database queries executed via fmdb. This prevents runaway queries from consuming resources indefinitely.
  • Input Validation and Complexity Limits: Validate user inputs that influence query parameters to prevent excessively complex or resource-intensive queries from being generated and executed by fmdb.