Attack Surface: Malicious Asset Processing (glTF, KTX2, etc.)
Description: Exploitation of vulnerabilities in Filament's parsing and processing of 3D model and texture formats (primarily glTF and KTX2, but also others it supports).
Filament Contribution: Filament is directly responsible for parsing and interpreting these file formats. The complexity of these formats and the potential for edge cases create a large attack surface within Filament's code.
Example: An attacker crafts a glTF file with a maliciously formed buffer view or accessor that triggers a buffer overflow in Filament's parsing code. Another example: a KTX2 file with invalid compression parameters leading to a denial of service within Filament.
Impact:
* Denial of Service (DoS)
* Arbitrary Code Execution (ACE) - Less likely, but possible within Filament's parsing logic
* Information Disclosure (potentially, depending on the vulnerability)
Risk Severity: High (Potentially Critical if ACE is possible)
Mitigation Strategies:
* Developer (Filament):
* Robust Input Validation: Implement comprehensive validation of all fields and data structures within the asset files. Check for valid ranges, sizes, and relationships between data elements within Filament's parsing routines.
* Fuzz Testing: Conduct extensive fuzz testing of Filament's parsing and processing code with a wide variety of malformed inputs. This is crucial for Filament.
* Memory Safety: Leverage Rust's memory safety features to the fullest extent. Minimize and very carefully audit any unsafe code within Filament's asset processing.
* Regular Security Audits: Perform regular, focused security audits of the asset processing code within Filament.
* Developer (Application using Filament):
* Pre-Validation: While helpful, pre-validation cannot replace Filament's internal validation. It can reduce the load, but Filament must still validate.
* Resource Limits: Impose limits on asset size/complexity. This mitigates DoS, but doesn't address code execution vulnerabilities.
* Sandboxing: Consider running Filament (or the asset loading part) in a sandbox. This contains the impact of a successful exploit.
* User:
* Source Assets Carefully: Obtain assets from trusted sources. This reduces the likelihood of encountering malicious assets.
Attack Surface: Malicious Shader Code (Impacting Filament and Driver)
Description: Exploitation of vulnerabilities through crafted shader code, targeting either Filament's shader handling or, more critically, the underlying graphics driver. Filament Contribution: Filament compiles GLSL shaders to SPIR-V and is the direct interface to the graphics driver. While the driver is external, Filament's interaction with it is a key part of the attack surface. Example: An attacker provides a GLSL shader that, after being processed by Filament and passed to the driver, triggers a known vulnerability in the graphics driver, leading to a system crash or privilege escalation. Another example: a shader designed to cause an infinite loop on the GPU, hanging the rendering process managed by Filament. Impact: * Denial of Service (DoS) - Affecting Filament and potentially the entire system. * Arbitrary Code Execution (ACE) - Potentially, through driver exploits initiated via Filament. * System Instability - Directly caused by Filament's interaction with the driver. Risk Severity: High (Potentially Critical if driver exploits lead to ACE) Mitigation Strategies: * Developer (Filament): * Shader Validation: Use a robust, up-to-date shader validator (like glslangValidator). This is Filament's responsibility. * SPIR-V Validation: Validate the generated SPIR-V code before passing it to the driver. This is a critical step for Filament. * Safe API Usage: Ensure Filament uses the graphics API in a safe, secure, and correct manner. Incorrect API usage by Filament can create vulnerabilities. * Minimize Attack Surface: Explore ways to limit the capabilities exposed to shaders through Filament's API, if feasible. * Developer (Application using Filament): * Shader Sanitization/Whitelisting: If possible, restrict shader features. This is often very difficult in practice, but can reduce risk if feasible. * GPU Timeouts: Implement timeouts for shader execution. This is a crucial defense against DoS attacks, and should be handled in conjunction with Filament. * User: * Driver Updates: Keep graphics drivers up-to-date. This is essential for mitigating driver-level vulnerabilities, which Filament can trigger. * Trusted Sources: If the application allows user-provided shaders, only allow this from highly trusted sources.