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PLAYBOOK · P3 · OWASP Agentic AI v1.1

Securing AI Tool Execution & Preventing Unauthorised Actions Across Supply Chains

Keep tool invocations on-policy and the upstream components trustworthy.

Goal: Prevent AI from executing unauthorised commands, misusing tools, or escalating privileges due to malicious manipulation, including across the agent’s supply chains.

Aligned with Step 3: Does the AI agent execute actions using tools, system commands, or external integrations? · 6 threats mitigated · 32 mitigations referenced

At a glance

THREATS COVERED
6
T2 · T3 · T4 · T11 · T16 · T17
NAVIGATOR STEP
P3
Step 3: Does the AI agent execute actions using tools, system commands, or external integrations?
MITIGATIONS
32
distinct Helmwart controls referenced across the three phases

Defence-in-depth chain

When tool misuse or an arbitrary-execution attempt arrives, Proactive controls (least-privilege tool scoping and just-in-time tool grants) enforce authorisation at the point of invocation. If a misuse attempt reaches the execution stage, Reactive controls (the code-generation review gate and reviewer decision summaries) gate risky tool calls on human approval. Detective controls (separation of actor and recorder and static analysis on generated code) produce a tamper-evident audit trail and flag policy-violating code for post-incident investigation.

ATTACK ARRIVES tool misuse PROACTIVE Tool scoping Just-in-time grants Sandboxed execution blocked INVOCATION DENIED REACTIVE Code review gate Decision summary Anomaly quarantine held for review HUMAN GATE DETECTIVE Actor / recorder split Static analysis Supply-chain SBOM alert AUDIT TRAIL INTACT attack passes attack passes OUTCOME signed + attributed

proactive Step 1: Restrict AI tool invocation, execution and apply supply-chain safeguards

  • Define an explicit tool allow-list for each agent and enforce it through a policy engine so no undeclared tool can be invoked.

  • Apply version control and peer review to prompt repositories, scripts, and memory definitions exactly as you would to application code.

    Helmwart controls: Code review gate
  • Require cryptographic identity verification for each agent before it is permitted to call any tool or external function.

  • Classify every data asset by sensitivity and enforce per-tool, per-agent allow-lists governing which data classes may be read or written.

    Helmwart controls: Data classification
  • Run every AI-invoked tool inside an isolated, containerised sandbox with no access to sensitive resources or the production network.

    Helmwart controls: gVisor
  • Apply strict CPU, memory, and syscall limits inside the sandbox to prevent resource exhaustion or privilege abuse.

  • Tear down and recreate the sandbox after each tool execution to prevent an attacker from establishing persistence or moving laterally.

    Helmwart controls: gVisor
  • When tools are called via inter-agent protocols such as A2A or MCP, sanitise responses, validate tool descriptions, and attest server identity before use.

  • Rate-limit all agent API calls and computationally expensive task invocations to prevent abuse and resource exhaustion.

    Helmwart controls: Rate limits and quotas
  • Block tool execution in real time when the agent's risk score exceeds a predefined threshold, keeping autonomy within policy bounds.

  • Grant tool access only at the moment it is needed and revoke it immediately upon completion, never persisting elevated permissions.

  • Digitally sign all agent cards, prompt templates, and model definitions, and publish a verifiable SBOM for every agent and its runtime components.

    Helmwart controls: Sigstore Agent SBOM
  • Bind tool-call parameters to a cryptographic attestation of the user's stated intent so invocations cannot drift from the original task.

    Helmwart controls: Intent attestation

reactive Step 2: Monitor & prevent tool misuse and supply-chain anomalies

  • Record every tool interaction with actor attribution and tamper-evident signatures to support forensic investigation.

  • Detect and isolate command-chaining sequences that would allow an agent to circumvent individual tool-access policies.

  • Gate high-impact tool executions (financial, medical, administrative) behind explicit human approval with a risk-prioritised review queue.

  • Maintain signed, detailed execution logs for every tool call so anomalies can be detected and investigations reconstructed accurately.

  • Block execution of AI-generated code with elevated privileges until a human reviewer has approved it.

    Helmwart controls: Code review gate
  • Flag any agent invoking the same tool at an abnormally high frequency within a short window, as this is a reliable indicator of abuse.

  • Monitor every tool interaction for unintended side effects and cross-audit outcomes against the agent's declared intent.

detective Step 3: Prevent AI resource exhaustion and supply-chain compromise

Source

OWASP Agentic AI: Threats and Mitigations v1.1 (Dec 2025), §Mitigation Strategies. Action text is taken verbatim or paraphrased from the canonical document; the Helmwart additions are the per-action mappings onto deployable mitigation entries.