What is Identity & Privilege Abuse (ASI03)?

In traditional software, we secure "Users." In Agentic AI, we must secure "Delegated Intent." ASI03 occurs when the security boundaries between the user, the agent, and the system infrastructure are blurred.

When a user grants an agent access to their email or cloud environment, they often grant it a "God-mode" token. If that agent is compromised via ASI01 (Goal Hijacking), the attacker doesn't just control the agent—they inherit the user’s full identity.

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The "Confused Deputy" in Multi-Agent Systems (MAS)

One of the most dangerous manifestations of ASI03 occurs in Agent-to-Agent (A2A) ecosystems. This is known as the "Confused Deputy" problem, updated for 2026.

The Scenario:

1. The Support Agent: A low-privilege agent designed to handle customer queries.
2. The Admin Agent: A high-privilege agent that can modify database records or issue refunds.
3. The Attack: An attacker sends a message to the Support Agent. The Support Agent, lacking strict output validation, forwards the request to the Admin Agent.
4. The Abuse: The Admin Agent "trusts" the Support Agent because they are both "internal." It executes the request (e.g., "Change the shipping address for order #1234 to [Attacker Address]") without re-verifying that the original user had the permission to make that change.

Credential Leaking and "Living Off the Context"

Agents often need to handle sensitive secrets (API keys, SSH keys, Bearer tokens) to perform their tasks. ASI03 vulnerabilities often arise when these secrets are mishandled:

• Leaking in Context: The agent accidentally prints an API key in its "Thought Process" or "Reasoning" logs, which are then stored in unencrypted log files.
• Token Hoarding: An agent is granted a long-lived OAuth token rather than a one-time-use token. If the agent's memory is poisoned (ASI06), the attacker can "extract" these stored credentials.

The Solution: Agent-First IAM (Identity & Access Management)

To mitigate ASI03, organizations must implement a Zero-Trust Architecture for Agents:

1. Ephemeral, Scope-Limited Tokens

Agents should never use "Master Keys." Instead, the orchestrator should issue Dynamic, Task-Specific Tokens.

• Example: If an agent needs to read one file from an S3 bucket, it should be issued a token that only permits s3:GetObject on that specific file path, expiring in 5 minutes.

2. Identity Attribution in A2A

Every message sent between agents must include a Cryptographic Proof of Origin.

• Use MTLS (Mutual TLS) or signed JWTs (JSON Web Tokens) for every inter-agent call.
• The Admin Agent must verify the "Chain of Custody" of a request, ensuring the end-user (not just the intermediate agent) has the requisite permissions.

3. Secrets Redaction Engines

Implement a "Secrets Proxy" between the model and the logs. Any string resembling a credential (regex for AKIA..., sk_live..., etc.) must be automatically masked before the agent’s reasoning is written to any persistent storage.

How to Audit for ASI03 Privilege Creep

Audit your agentic cluster by performing a Privilege Escalation Test:

1. Identify the agent with the lowest permissions (e.g., a "Read-Only" documentation bot).
2. Attempt to force that agent to trigger a tool call in a higher-privilege agent (e.g., the "Billing Bot").
3. If the Billing Bot executes the request without checking the original user's authentication context, you have an ASI03 vulnerability.

Related Articles:

• [ASI04: Agentic Supply Chain - Vulnerabilities in MCP and Connectors]
• [ASI07: Insecure Inter-Agent Communication - Securing the A2A Fabric]
• [ASI09: Human-Agent Trust Exploitation - Social Engineering AI Identities]