Attack Surface Analysis for bevyengine/bevy

Attack Surface: Untrusted Component Data

Description: Maliciously crafted data within ECS components, loaded from external sources (save files, network messages, etc.), can trigger unexpected behavior.
How Bevy Contributes: Bevy's core ECS architecture relies on components as the primary data storage mechanism. The engine itself doesn't enforce strict validation of component data, leaving this responsibility entirely to the developer. This is a fundamental design aspect of Bevy.
Example:
- A save file contains a component representing a player's inventory. An attacker modifies the save file to include an item with an extremely large "weight" value (e.g., a u64 set to u64::MAX). When the game loads this inventory, it could lead to integer overflows or memory allocation issues.
- A networked game uses a component to represent player position. An attacker sends a crafted network message with an invalid position (e.g., NaN for floating-point coordinates), causing the game to crash or behave unpredictably.
Impact: Denial of Service (DoS), Logic Errors, Potential (indirect) Code Injection.
Risk Severity: Critical (if untrusted data sources are used) / High (if data sources are partially trusted).
Mitigation Strategies:
- Developer:
  - Comprehensive Input Validation: Implement rigorous validation for all component data loaded from untrusted sources. This includes type checking, bounds checking, and sanitization. Use a schema-based validation approach if possible.
  - Safe Deserialization: Use secure deserialization methods. Avoid deserializing directly to dyn Any from untrusted sources. Consider using formats like bincode with appropriate configuration for size limits.
  - Defensive Programming: Write systems that are robust to invalid component data. Assume that component data could be malicious and handle potential errors gracefully.
  - Fuzz Testing: Fuzz test the component loading and deserialization process to identify potential vulnerabilities.

Attack Surface: Resource Exhaustion (Entities/Components)

Description: An attacker can cause a denial-of-service by triggering the creation of an excessive number of entities or components.
How Bevy Contributes: Bevy's ECS allows for dynamic creation of entities and components. The engine doesn't inherently limit the number of entities or components that can be created. This is a core feature of the ECS pattern.
Example:
- In a multiplayer game, an attacker sends a flood of network messages requesting the creation of new entities (e.g., projectiles, enemies). This overwhelms the server, causing it to crash or become unresponsive.
- A moddable game allows users to create custom content. An attacker creates a mod that spawns a massive number of entities when loaded, crashing the game.
Impact: Denial of Service (DoS).
Risk Severity: High (especially in networked games) / Medium (in single-player games with modding, but still included due to Bevy's direct involvement).
Mitigation Strategies:
- Developer:
  - Rate Limiting: Implement rate limiting on entity/component creation, especially for actions triggered by network messages or user input.
  - Resource Quotas: Set limits on the total number of entities or components that can be created by a particular user, connection, or mod.
  - Sanity Checks: Implement checks to ensure that entity/component creation requests are reasonable. For example, limit the number of projectiles that can be fired within a short time period.

Attack Surface: Untrusted Plugins

Description: Third-party Bevy plugins can introduce any of the above vulnerabilities, depending on their functionality.
How Bevy Contributes: Bevy's plugin system allows for easy extension, but this also means that untrusted code can be easily integrated directly into the Bevy runtime. This is a key architectural feature.
Example: A plugin that adds a new networking protocol has a vulnerability in its message handling, allowing for RCE.
Impact: Varies depending on the plugin; could include any of the above impacts (DoS, logic errors, etc.).
Risk Severity: High (if using untrusted plugins).
Mitigation Strategies:
- Developer:
  - Vet Plugins Carefully: Thoroughly review the source code of any third-party plugins before using them. Prioritize plugins from trusted sources and with a good reputation.
  - Isolate Plugins (Ideally): If possible (though difficult within Bevy's architecture), try to isolate plugins to limit their potential impact. This is a significant challenge.
  - Regular Updates: Keep plugins updated.