Skip to content

Latest commit

 

History

History
65 lines (54 loc) · 5.73 KB

threat-modeling.md

File metadata and controls

65 lines (54 loc) · 5.73 KB

Threat Model Analysis for ruby-concurrency/concurrent-ruby

Threat: Data Race Exploitation

  • Description: An attacker crafts malicious input or manipulates network traffic to trigger a data race condition. They send multiple concurrent requests designed to exploit timing windows where shared data is in an inconsistent state, bypassing security checks (e.g., rate limiters, permissions) or corrupting data.
    • Impact: Data corruption, unauthorized access, privilege escalation, denial of service (if the race leads to a crash), or other application-specific vulnerabilities.
    • Affected Component: Any component using shared mutable state without proper synchronization:
      • Direct use of shared variables without Atomic wrappers.
      • Incorrect use of Mutex or ReadWriteLock (missing locks, incorrect release, inconsistent locking order).
      • Custom concurrent code accessing shared resources.
    • Risk Severity: Critical to High (depending on the data and consequences of corruption).
    • Mitigation Strategies:
      • Use concurrent-ruby's atomic data structures (AtomicFixnum, AtomicBoolean, AtomicReference, etc.).
      • Employ Mutex or ReadWriteLock consistently and correctly. Ensure consistent locking order to prevent deadlocks.
      • Prefer immutable data structures.
      • Thoroughly review and test concurrent code. Use static and dynamic analysis tools (e.g., ThreadSanitizer) to detect data races.
      • Robust input validation and sanitization.

Threat: Deadlock-Induced Denial of Service

  • Description: An attacker sends requests designed to trigger a deadlock in the application's concurrency logic, exploiting poorly designed locking or resource dependencies.
    • Impact: Application becomes unresponsive (DoS), requiring a restart.
    • Affected Component: Primarily code using Mutex or ReadWriteLock incorrectly, especially with multiple locks or resource dependencies. Also potentially Condition variables if misused.
    • Risk Severity: High
    • Mitigation Strategies:
      • Carefully design locking to avoid circular dependencies. Always acquire locks in a consistent order.
      • Use timeouts on lock acquisition (Mutex#try_lock with a timeout).
      • Monitor for deadlocks in production.
      • Use deadlock detection tools during development/testing.

Threat: Thread Pool Exhaustion (Resource Exhaustion)

  • Description: An attacker sends many requests that trigger the creation of new threads/processes within a concurrent-ruby thread pool. If the pool is unbounded or has a high limit, this exhausts system resources.
    • Impact: Application slowdown, crashes, denial of service (DoS) to the application and potentially other applications.
    • Affected Component: ThreadPoolExecutor and subclasses (FixedThreadPool, CachedThreadPool, ImmediateExecutor) without appropriate size limits. Also Promise and Future if many are created without being consumed.
    • Risk Severity: High
    • Mitigation Strategies:
      • Use bounded thread pools (FixedThreadPool) with a carefully chosen maximum size.
      • Monitor resource usage (CPU, memory, threads) and adjust pool sizes.
      • Implement backpressure (rate limiting, request queuing).
      • Use timeouts on Promise and Future objects.

Threat: Unhandled Exception Leading to Resource Leak or Inconsistent State

  • Description: An attacker triggers an unhandled exception within a concurrent task (e.g., via invalid input). If uncaught, the task terminates abruptly, potentially leaving resources in an inconsistent state or leaking resources.
    • Impact: Data corruption, resource leaks, denial of service (if resources are exhausted), or other vulnerabilities.
    • Affected Component: Any code within a concurrent-ruby managed thread/process (e.g., within a Future, Promise, or a task in a ThreadPoolExecutor).
    • Risk Severity: High to Medium (depending on the consequences; promoted to High because of the direct involvement of concurrent-ruby and potential for widespread impact).
    • Mitigation Strategies:
      • Always wrap concurrent task code in begin...rescue blocks.
      • Use concurrent-ruby's error handling (Future#rescue, Promise#rescue).
      • Log exceptions caught within concurrent tasks.
      • Implement proper resource cleanup (e.g., ensure blocks).

Threat: TOCTOU Vulnerability Exploitation

  • Description: An attacker exploits a time-of-check to time-of-use (TOCTOU) vulnerability. They send a request that passes an initial check, then quickly send another to modify the state before the first request's action completes, invalidating the check.
    • Impact: Bypass of security checks, unauthorized access, privilege escalation.
    • Affected Component: Any code that performs a check and then an action without ensuring the state hasn't changed in between. This is a pattern of incorrect usage, exacerbated by concurrency.
    • Risk Severity: Critical to High (depending on the security check).
    • Mitigation Strategies:
      • Use atomic operations or locks (e.g., Mutex) to make the check-and-act sequence indivisible.
      • Avoid assumptions about state between check and action.
      • Re-check critical conditions immediately before the action, if possible.