NAVIRA LABS • RESEARCH GUIDE 002

Agentic IAM: Scoped Delegation & Confused Deputy Prevention

Autonomous AI agents with tool calling capabilities act as privileged intermediaries between users and backends. We demonstrate how an unprivileged user can leverage prompt persuasion and multi-step reasoning manipulation to turn the agent into a confused deputy that modifies restricted database records.

Author: Navira Security ResearchTarget: Multi-Agent Autonomous SystemsRead time: 10 min

The Confused Deputy Vulnerability

An enterprise internal assistant has access to both read-only company docs and a database modification tool reserved for DevOps. A standard employee tricks the agent into modifying cluster firewall rules.

Execution Chain:
User Prompt → Planning Agent → Tool Dispatcher → Database / API / Cloud Infrastructure

Hardened IAM Delegation Blueprint

Enforce dual-token validation on every tool call. The tool dispatcher must check both the agent's machine identity and the requesting human principal's OAuth JWT:

scoped_tool_dispatcher.tstypescript
interface UserContext {
  userId: string;
  roles: string[];
  token: string;
}

// Scoped Tool Dispatcher enforcing User-Level Authorization Tokens
export async function executeAgentTool(
  toolName: string, 
  params: Record<string, unknown>, 
  user: UserContext
) {
  // 1. Verify user RBAC permissions for the target tool
  const isAuthorized = await checkUserPermission(user.userId, toolName);
  if (!isAuthorized) {
    throw new Error(`Security Error: User ${user.userId} is not authorized to invoke tool ${toolName}`);
  }

  // 2. High-risk tool confirmation gate (HITL)
  if (isHighRiskTool(toolName)) {
    return await requestHumanInTheLoopConfirmation(user.userId, toolName, params);
  }

  // 3. Execute tool using user-scoped token (not global service account)
  return await dispatchToBackend(toolName, params, { authorization: `Bearer ${user.token}` });
}

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