LLM Application Penetration Testing

Why it matters

An LLM application is far more than a model — it is prompts, plugins, APIs, data stores and the code that wires them together, and each layer carries both AI-specific and classic web risks. Attackers exploit exactly where those two worlds meet.

Testing the whole stack against the OWASP Top 10 for LLM Applications, alongside traditional web and API security, is the only way to see the real, exploitable risk in a generative-AI product.

What we test

• Prompt injection & output handling
• Insecure plugin & tool integration
• Sensitive information disclosure
• Excessive agency & over-permissioning
• Traditional web/API flaws in the stack
• Model denial-of-service & cost abuse

Common vulnerabilities we uncover

• Prompt injection and insecure output handling
• Insecure plugin and tool integration
• Sensitive information disclosure
• Excessive agency and over-permissioning
• Model denial-of-service and cost abuse
• Classic web/API flaws in the surrounding stack

Our LLM Application Penetration Testing methodology

1. Scoping & rules of engagement. We agree objectives, targets and boundaries for your llm application penetration testing, so testing is safe, authorized and focused on what matters to your business.
2. Reconnaissance & mapping. We enumerate the full attack surface in scope, building a complete picture before any exploitation begins.
3. Manual exploitation. Our senior testers chain vulnerabilities by hand — going far beyond automated scanners — to prove real, demonstrable impact.
4. Analysis & reporting. Every finding is triaged, risk-rated with CVSS and written up with a copy-paste reproduction and clear remediation.
5. Remediation support & free retest. We support your team through the fixes and retest the remediated issues to confirm they are genuinely closed.

Tools & techniques

We test LLM applications with combined AI and traditional application-security tooling. Alongside prompt-injection and output-handling tests, we run full web and API penetration testing of the surrounding stack: authentication and authorization, injection, SSRF, insecure plugins and business logic. We instrument prompts, tools and backend calls together, because the highest-impact findings usually emerge where AI-specific and classic web vulnerabilities meet.

When you need LLM Application Penetration Testing

• Before launching a generative-AI product, chatbot or copilot
• When an LLM feature is added to an existing web or SaaS application
• For products handling user data, payments or regulated information
• To meet security review and OWASP LLM Top 10 requirements

What you receive

• Full-stack LLM app findings
• OWASP LLM Top 10 coverage
• Reproducible PoCs & remediation
• Free retest after remediation

What’s included in your report

Every llm application penetration testing engagement concludes with a comprehensive, board-ready report and a working session to walk your team through it. Your report includes:

• An executive summary with overall risk posture for non-technical stakeholders
• Detailed technical findings, each with a step-by-step, copy-paste reproduction
• CVSS v3.1 severity ratings and business-impact context for every issue
• Prioritized, actionable remediation guidance your engineers can apply directly
• A complimentary retest to confirm fixes and update finding status
• A formal attestation letter for customers, auditors and compliance programs

Standards & frameworks

Outcomes you can expect

After your llm application penetration testing, you will have clear, evidence-based visibility into your real security risk — not a scanner’s guesswork. You will know exactly which weaknesses an attacker could exploit, what the business impact would be, and the precise steps to fix them in priority order. Teams use our findings to close critical gaps, satisfy customer and regulator security requirements, and demonstrate due diligence to their board. With a complimentary retest included, you also get documented proof that the issues are genuinely resolved.

Engagement details & logistics

Every llm application penetration testing starts with a short, no-obligation scoping call to understand your goals, environment and constraints, followed by a fixed-price proposal and a clear statement of work. Most engagements are delivered fully remotely, with on-site work arranged where it genuinely adds value. Throughout testing we maintain an agreed communication cadence and escalate any critical, high-impact finding to you immediately rather than waiting for the final report. All work is performed under a signed NDA with strict data-handling controls, using safe, non-disruptive techniques and carefully coordinated rules of engagement to protect your production systems. On completion you receive your report and a walkthrough session, followed by a complimentary retest once your fixes are in place. Typical engagements are booked one to three weeks in advance, and urgent or pre-deadline testing can often be accommodated — just ask at hi@agentoffense.com.

Why organizations choose AgentOffense for LLM Application Penetration Testing

Our llm application penetration testing is delivered by senior offensive-security engineers who test the way real attackers do — manually, creatively and with a relentless focus on proving genuine, demonstrable impact. Here is what sets our engagements apart:

• Manual, exploit-driven testing that chains vulnerabilities the way a real attacker would, going far beyond what automated scanners can find.
• Reproducible proof for every finding, with copy-paste reproduction steps your engineers can follow and independently verify.
• Honest severity calibration so you invest in fixing what genuinely matters and avoid wasting effort on false positives and noise.
• Clear, business-focused reporting that speaks to engineers and executives alike, tying every issue to real-world impact.
• A complimentary retest included, so you get documented proof that your fixes actually close the attack path.
• Responsible, collaborative delivery with a named point of contact and secure handling of all data throughout the engagement.

Explore related services

LLM Application Penetration Testing is frequently scoped alongside our other offensive-security services for broader coverage. Explore related engagements that complement it:

• Prompt Injection Testing — Prompt injection testing — direct and indirect injection across every untrusted input path, including RAG and…
• RAG Pipeline Security Assessment — RAG security assessment — vector-store poisoning, context leakage, access-control gaps and retrieval-based prompt injection across your…
• Web Application Penetration Testing — Manual web application penetration testing against the OWASP Top 10 and business-logic flaws. Exploit-driven testing with…

Frequently asked questions