threat-modeling.md

Threat Model Analysis for crossbeam-rs/crossbeam

Threat: Data Race Exploitation in Crossbeam Concurrency

• Description: An attacker exploits a data race condition that arises within concurrent code utilizing crossbeam primitives. While Rust's borrow checker mitigates many data races, incorrect use of unsafe blocks or subtle concurrency bugs when managing shared mutable state alongside crossbeam primitives can still introduce data races. An attacker might trigger specific execution paths in crossbeam-based concurrent logic to exploit these races for memory corruption.
• Impact: Memory corruption can lead to arbitrary code execution, privilege escalation, data breaches, or denial of service.
• Affected Crossbeam Component: Indirectly related to all crossbeam components when used with unsafe code or complex shared mutable state management in concurrent contexts.
• Risk Severity: Critical
• Mitigation Strategies:
  • Minimize or eliminate unsafe code blocks in concurrent sections.
  • Rigorous code reviews specifically focusing on concurrency and memory safety in crossbeam usage.
  • Utilize memory sanitizers (e.g., miri, AddressSanitizer) during development and testing of crossbeam-based concurrent code.
  • Implement thorough testing of concurrent code paths, including stress testing, to expose potential data races.

Threat: Logical Race Condition Leading to Inconsistent State in Crossbeam Applications

• Description: An attacker leverages a logical race condition within the application's concurrent logic built using crossbeam primitives. This occurs when the intended outcome of operations depends on the non-deterministic ordering of concurrent tasks orchestrated by crossbeam. Exploiting these races can lead to inconsistent application state, bypassing security checks, or incorrect data processing within the crossbeam-managed concurrency.
• Impact: Data corruption, business logic bypass, unauthorized access, incorrect data processing, potentially leading to financial loss or reputational damage.
• Affected Crossbeam Component: General usage of crossbeam primitives for concurrency management (channels, atomics, queues, scopes).
• Risk Severity: High
• Mitigation Strategies:
  • Employ careful design and thorough review of concurrent algorithms and application logic that utilize crossbeam.
  • Utilize appropriate synchronization mechanisms provided by crossbeam or Rust standard library to enforce correct ordering and prevent logical race conditions.
  • Implement comprehensive testing of concurrent workflows and edge cases within crossbeam-based applications to identify and eliminate race conditions.
  • Consider using higher-level abstractions or libraries built on top of crossbeam if they simplify concurrency management and reduce the likelihood of introducing logical errors.

Threat: Deadlock leading to Denial of Service via Crossbeam Synchronization

• Description: An attacker crafts specific input or triggers a sequence of actions that causes the application to enter a deadlock state due to improper use of crossbeam channels or other synchronization primitives. This can occur when concurrent tasks using crossbeam channels or locks become blocked indefinitely, waiting for each other in a circular dependency. The deadlock renders the application unresponsive and unable to process further requests.
• Impact: Denial of service, application unavailability, significant business disruption.
• Affected Crossbeam Component: crossbeam_channel, crossbeam_sync (e.g., mutexes, condition variables if used in conjunction).
• Risk Severity: High
• Mitigation Strategies:
  • Carefully design synchronization logic in crossbeam-based concurrent code to strictly avoid circular dependencies in resource acquisition or channel communication.
  • Implement timeouts for channel operations or other blocking operations within crossbeam concurrency patterns to prevent indefinite blocking.
  • Incorporate deadlock detection mechanisms into the application (if feasible and performant for the specific concurrency model).
  • Conduct thorough testing of concurrent scenarios, specifically focusing on identifying potential deadlock situations in crossbeam-driven workflows.

Threat: Unbounded Channel Memory Exhaustion Denial of Service

• Description: An attacker floods an unbounded channel (crossbeam_channel::unbounded) with messages, deliberately exceeding available memory and causing the application to crash due to out-of-memory errors. The attacker might exploit a publicly accessible endpoint or an internal message queue to inject a massive volume of messages into a crossbeam unbounded channel.
• Impact: Denial of service, application crash, potential system instability and wider infrastructure impact.
• Affected Crossbeam Component: crossbeam_channel::unbounded.
• Risk Severity: High
• Mitigation Strategies:
  • Avoid using unbounded channels (crossbeam_channel::unbounded) in untrusted environments or when handling potentially large volumes of external or uncontrolled input within crossbeam applications.
  • Prefer using bounded channels (crossbeam_channel::bounded) with carefully considered capacity limits to restrict memory usage.
  • Implement backpressure mechanisms to control message producers and prevent channel overflow in crossbeam communication patterns.
  • Continuously monitor channel size and overall memory usage of the application to proactively detect and respond to potential memory exhaustion attacks targeting crossbeam unbounded channels.