Attack Surface: 1. Malicious Input Vectors (Index Building & Querying)
- Description: Attackers craft specific input vectors to exploit Faiss's internal algorithms, causing various negative effects.
- How Faiss Contributes: This is fundamental to Faiss. Faiss's core purpose is processing vectors, and its algorithms are the direct target.
- Example: An attacker submits a query vector designed to trigger a division-by-zero or infinite loop within Faiss's distance calculations. Or, during index building, vectors are crafted to create unbalanced clusters, degrading performance.
- Impact:
- Denial of Service (DoS): Crashing Faiss, exhausting memory, or causing excessive CPU usage.
- Information Leakage (Indirect): Revealing index structure or data distribution.
- Index Corruption (Rare): Potentially corrupting the index.
- Risk Severity: High (DoS is very likely).
- Mitigation Strategies:
- Strict Input Validation: Validate vector dimensionality, data type, and value ranges (min/max, norms). Reject invalid vectors.
- Fuzz Testing: Use fuzzing tools to generate a wide variety of vectors to test Faiss's robustness. This is crucial.
- Resource Monitoring: Monitor Faiss's CPU and memory usage. Set limits and alerts.
- Rate Limiting: Limit the rate of index building and querying.
- Input Sanitization: Sanitize inputs.
Attack Surface: 2. Index Deserialization Vulnerabilities
- Description: Attackers provide a malicious Faiss index file that, when loaded, exploits vulnerabilities in the deserialization process.
- How Faiss Contributes: Faiss's own serialization/deserialization mechanism is the direct attack vector.
- Example: An attacker uploads a crafted index file that, when loaded by Faiss, triggers a buffer overflow or executes arbitrary code.
- Impact:
- Remote Code Execution (RCE): The attacker gains full control of the server.
- Denial of Service (DoS): Crashing Faiss during loading.
- Risk Severity: Critical (RCE is a major threat).
- Mitigation Strategies:
- Avoid Untrusted Sources: Never load Faiss indexes from untrusted sources. This is the primary defense.
- Secure Deserialization (If Necessary): If unavoidable, investigate secure deserialization methods or build a secure wrapper. This is complex.
- Sandboxing: Load the index in a sandboxed environment.
- Input Validation: Validate loaded index.
Attack Surface: 3. Data Poisoning (Index Modification)
- Description: If index modification is allowed, attackers with sufficient privileges can add/modify vectors to manipulate search results.
- How Faiss Contributes: Faiss's APIs for adding, removing, and updating vectors are the direct means of attack.
- Example: An attacker adds many vectors similar to a specific item to artificially boost its ranking in a recommendation system.
- Impact: Biased/Incorrect Results: Search results are skewed.
- Risk Severity: High (impact depends on the application; can be critical).
- Mitigation Strategies:
- Strict Access Control: Implement robust authentication and authorization. Follow the principle of least privilege.
- Auditing: Log all index modification operations.
- Input Validation: Validate all vectors added to the index.
- Description: Attackers overwhelm Faiss, causing resource exhaustion. This focuses on aspects directly related to Faiss's functionality.
- How Faiss Contributes: Faiss's processing of queries and its index management consume resources.
- Example:
- Query Flooding (Targeting Faiss): Sending a massive number of valid but computationally expensive Faiss queries. This is distinct from a generic network flood.
- Index Bloating (If Modification Allowed): Adding a huge number of vectors to exhaust memory/disk used by Faiss.
- Impact: The Faiss-based service becomes unavailable.
- Risk Severity: High.
- Mitigation Strategies:
- Rate Limiting (Faiss-Specific): Limit the rate of Faiss queries, potentially with different limits based on query complexity.
- Resource Monitoring (Faiss-Specific): Monitor Faiss's internal resource usage (memory allocated to the index, etc.).
- Limit Index Size (If Modification Allowed): Set limits on the total index size or the number of vectors.
- Data Validation (If Modification Allowed): Validate incoming vectors before adding them.