Field Notes / AI Security
AI Red Teaming vs Penetration Testing: What the Difference Actually Means for Your AI System.
A penetration test asks whether an attacker can break into your systems. AI red teaming asks whether an attacker can make your model, copilot or agent do something it should never do. They use different playbooks, find different failures, and one does not substitute for the other. Here is where each one applies, mapped to the frameworks your auditors already cite.
01 What a pen test tests
penetration test is a controlled attack on your infrastructure and applications. A tester takes the position of an adversary and tries to gain unauthorised access, escalate privilege, and reach data that should be out of reach. The discipline is mature. It runs against published methodologies such as the Penetration Testing Execution Standard and the OWASP Web Security Testing Guide, and in the United Kingdom it is accredited through schemes like CREST PTES / OWASP WSTG .
A finding from a pen test is a vulnerability with a name. An SQL injection point. A server missing a patch. An access control that lets a standard user reach an admin function. A password policy that never forced a change. Each one is a defect in how the system was built or configured, and each one has a fix that closes it. You can retest and confirm the hole is gone, because the hole was concrete.
When your AI feature runs on ordinary infrastructure, and it does, a pen test covers that infrastructure well. The hosting, the API gateway, the authentication, the databases behind the model: all of it is fair game and all of it should be tested. The gap opens at the model itself, because the model is not vulnerable in the way a server is. It is suggestible in a way a server is not.
02 What AI red teaming tests
I red teaming is a goal-oriented attack on the behaviour of an AI system. The tester does not look for a broken function. They look for a way to make the model act against its own instructions, and they treat the model, the data it can reach, and the tools it can call as one attack surface. The reference catalogue is the OWASP Top 10 for Large Language Model Applications, refreshed for 2025, and the adversary tactics are mapped in MITRE ATLAS, the AI counterpart to the ATT&CK matrix your SOC already knows MITRE ATLAS .
The 2025 OWASP list names the weakness classes an AI red team works through. They are not bugs in the classic sense. They are the ways a system that reads language and takes action can be turned against its owner.
| OWASP LLM Top 10 (2025) | What it means in plain terms |
|---|---|
| LLM01 Prompt Injection | An attacker plants instructions the model obeys, often hidden in content it reads |
| LLM02 Sensitive Information Disclosure | The model reveals data, secrets or its own configuration it should not |
| LLM03 Supply Chain | A compromised model, dataset or plugin brings the risk in with it |
| LLM04 Data and Model Poisoning | Tampered training or fine-tuning data bends the model's behaviour |
| LLM05 Improper Output Handling | Downstream systems trust model output and execute what they should not |
| LLM06 Excessive Agency | An agent holds more permission or tool access than the task needs |
| LLM07 System Prompt Leakage | The hidden instructions steering the model are extracted by an attacker |
| LLM08 Vector and Embedding Weaknesses | The retrieval layer behind the model is manipulated or leaks data |
| LLM09 Misinformation | The model produces confident, wrong output that a user acts on |
| LLM10 Unbounded Consumption | An attacker drives cost or denial of service through the model itself |
A finding here rarely looks like a vulnerability report. It looks like a transcript. The tester shows the exact input that made the copilot ignore its guardrails, or the sequence that made an agent call a tool it should have refused. The fix is rarely a patch. It is a change to the system prompt, the tool permissions, the input handling, or the boundary between what the model reads and what it is allowed to do.
03 Side by side
Read the two disciplines across the dimensions that decide which you need. They share the mindset of the attacker. They diverge on almost everything else.
| Penetration testing | AI red teaming | |
|---|---|---|
| Core question | Can an attacker get in? | Can an attacker make the AI misbehave? |
| Target | Networks, servers, applications, APIs | Models, copilots, agents, the data and tools around them |
| A finding is | A named technical vulnerability | A manipulated output or an unintended action |
| Frameworks | PTES, OWASP WSTG, CREST | OWASP LLM Top 10, MITRE ATLAS, NIST AI RMF |
| The fix is usually | A patch, a config change, an access rule | A prompt, permission, input or boundary change |
| Repeatability | Deterministic; the hole is there or it is not | Probabilistic; the same input can vary by run |
| Maturity | Decades of accredited practice | An emerging discipline, moving fast |
The line that matters most is repeatability. A pen tester confirms a fix by rerunning the attack and watching it fail. An AI red teamer works against a system that can answer the same prompt two ways, so a single clean run proves little. Testing has to probe the behaviour many times, across variations, which is why AI red teaming leans on adversarial creativity rather than a scanner alone.
04 Which one you need
tart with what you have shipped. If you run standard applications and infrastructure with no AI in the path, a penetration test is the right test and AI red teaming does not apply yet. If you have deployed a model, a copilot or an agent that customers or staff actually use, you have opened a surface a pen test was never built to cover, and you need both.
A short way to decide. Ask what the AI can reach and what it can do. A model that only answers questions from a fixed, trusted source and takes no action carries modest risk, and a pen test of the surrounding application may be enough for now. A model that reads content you do not control, holds tools it can call, or acts on behalf of a user needs an AI red team, because every one of the OWASP LLM classes above is now in play.
Regulation is closing the same gap. The UK Code of Practice for the Cyber Security of AI, published by DSIT with the NCSC, sets adversarial testing of AI systems as a baseline expectation across the lifecycle, and the NIST AI Risk Management Framework asks the same in its Generative AI Profile. Boards that treated AI testing as optional in 2024 are being asked to evidence it in 2026 DSIT / NCSC Code of Practice .
05 How they fit together
The honest answer is that they belong on the same engagement. The worst attack paths cross the boundary between them. A prompt injection tricks an agent into calling an internal API, and from there the attack becomes a classic privilege problem a pen tester recognises. A misconfigured database found in a pen test turns out to hold the training data that poisons a model. Read the two sets of findings apart and you miss the chain. Read them together and the real risk stands out.
If you have shipped an AI feature and you are not certain which test it needs, that uncertainty is the finding. Start with a free audit. We tell you where your exposure sits across both disciplines, then give you a fixed price to close it.
References
Sources
- OWASP. Top 10 for Large Language Model Applications, 2025 (v2.0). genai.owasp.org
- MITRE. ATLAS (Adversarial Threat Landscape for Artificial-Intelligence Systems). atlas.mitre.org
- NIST. AI Risk Management Framework (AI RMF 1.0) and the Generative AI Profile (NIST AI 600-1). nist.gov
- NIST. Adversarial Machine Learning: A Taxonomy and Terminology of Attacks and Mitigations (NIST AI 100-2e2025). csrc.nist.gov
- DSIT and NCSC. Code of Practice for the Cyber Security of AI. United Kingdom, 2025. gov.uk
- PTES. Penetration Testing Execution Standard, technical guidelines. pentest-standard.org
- OWASP. Web Security Testing Guide (WSTG). owasp.org