42Crunch for LLM gateway boundary test
What middleBrick covers
- Black-box LLM gateway scanning with adversarial prompts
- Risk scoring from A to F with prioritized findings
- Supports authenticated scans with header allowlist
- OpenAPI spec parsing and cross-reference with runtime data
- CI/CD integration via CLI and GitHub Action
- Continuous monitoring and diff detection across scans
Overview of LLM Gateway Boundary Testing
An LLM gateway sits in front of language models to enforce guardrails, route requests, and manage authentication. Boundary testing evaluates what an untrusted prompt can cause the gateway to reveal or execute. middleBrick scans this boundary using adversarial prompts designed to probe system instructions, data handling, and tool use without sending destructive payloads.
How middleBrick Approaches LLM Security Testing
The scanner runs black-box checks focused on the gateway surface, not the model internals. It submits text-only prompts aligned to LLM security testing, including system prompt extraction, instruction override attempts, DAN and roleplay jailbreaks, data exfiltration probes, token smuggling, and nested instruction injection. Each probe is non-intrusive and read-only, avoiding any impact on downstream services or models.
Mapping to Standards and Practical Coverage
middleBrick maps findings to OWASP API Top 10 (2023), which covers common risks around prompt injection, data exposure, and unsafe handling of LLM features. The tool helps you prepare for security reviews aligned with SOC 2 Type II controls relevant to access management and auditability. Findings related to unsafe consumption surface issues that support audit evidence for secure AI gateway design.
Integration Friction and Time-to-Value
middleBrick operates as a self-service scanner with minimal integration overhead. You submit a reachable gateway URL, and results appear in under a minute via the dashboard, CLI, or MCP server. There are no agents, SDKs, or code access required, which reduces setup complexity. The scanner enforces domain verification for authenticated scans, ensuring only authorized evaluators test environments that accept credentials.
Limitations and Responsible Use
middleBrick does not perform active exploitation such as SQL injection or command injection, as those lie outside its scope. It does not detect business logic flaws unique to your domain, and it cannot replace a human pentester for high-stakes audits. The tool surfaces findings relevant to gateway security but does not fix, patch, or block identified issues; remediation guidance is provided for further investigation.