Enterprise AI Threat Model — Part II | AetherStaff
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Enterprise Agent Engineering · Threat Modeling Reference
Chapter 06B · Threat Model · Abuse Cases

Enterprise AI abuse cases and attack paths

Part II translates the architecture into concrete adversarial scenarios, showing how malicious inputs and weak controls can become enterprise impact.

Chapter 6B translates architecture into concrete abuse cases and attack paths. Each scenario describes attacker preconditions, path, target, expected controls, observability, and residual risk.

6B.1 Attack surface inventory

SurfaceEntry pointsPrimary threats
User interactionChat, API, file upload, email, collaboration toolsInjection, impersonation, resource abuse
Context and retrievalSearch, knowledge stores, websites, documents, memoryIndirect injection, poisoning, unauthorized retrieval
Model layerPrompts, routing, fallback, fine-tuning, inference APIExtraction, policy bypass, unsafe fallback, supply chain
Agent runtimePlanning, handoffs, loops, memory, code executionExcessive agency, propagation, denial of service
Capabilities and connectorsAPIs, queues, RPA, databases, webhooksPrivilege escalation, duplicate action, SSRF, tampering
Telemetry and evaluationLogs, traces, datasets, feedbackOver-collection, tampering, privacy leakage

6B.2 Abuse case — Indirect prompt injection

Objective: use a trusted business document or external page to manipulate an agent into revealing data or invoking a tool.

  1. Attacker inserts hidden or visible instructions into a document, email, ticket, or webpage.
  2. The content is retrieved as evidence for a legitimate task.
  3. The model interprets the malicious text as an instruction.
  4. The agent requests a capability or external destination not required by the task.
  5. If policy and egress controls are weak, data is exposed or enterprise state is changed.
Control pointExpected mitigation
IngestionSource trust, content classification, malware and injection signals
Context assemblyInstruction/evidence separation, minimization, provenance
AgentTask-bound tool allowlist and bounded plan
PolicyIndependent authorization for resource, action, and destination
ConnectorSchema, egress allowlist, DLP, post-condition verification

6B.3 Abuse case — Sensitive data exfiltration

An attacker uses repeated questions, tool calls, memory retrieval, or external destinations to reconstruct protected information. The threat may come from a compromised user, malicious insider, poisoned content, or over-permissioned agent.

  • Enumerate accessible sources and infer schema.
  • Request progressively broader context.
  • Exploit summaries or embeddings that preserve hidden content.
  • Encode data in URLs, tool parameters, generated files, or logs.
  • Use cross-tenant cache, memory, or telemetry leakage.

Mitigation requires pre-retrieval authorization, field minimization, DLP, output classification, destination control, query-volume analytics, and tenant-isolated stores.

6B.4 Abuse case — Excessive agency

A legitimate or compromised user gives a broad goal. The agent decomposes it into high-impact actions using powerful tools, weak approval, or long-running autonomy. No single step appears malicious, but the combined behavior creates unacceptable impact.

Excessive agency pathBroad goal becomes unauthorized enterprise effect
Broad User Goal
Unbounded Planner
Broad Tool Scope
Weak Approval
Repeated Actions
Resource Expansion
Partial Failures
Business Impact

Controls include task classes, action budgets, resource limits, maximum step counts, explicit approvals, capability-specific identities, post-condition verification, and emergency suspension.

6B.5 Abuse case — Tool parameter manipulation

The attacker does not need to invoke an unauthorized tool if they can manipulate target identifiers, amounts, recipients, query filters, or destinations within an allowed capability. The threat model must therefore cover parameter integrity, not only tool names.

Example parameter substitution threat
{
  "allowed_capability":"crm.account.note.create-draft",
  "expected_account":"AC-1092",
  "model_supplied_account":"AC-8821",
  "attack":"identifier substitution",
  "required_control":[
    "bind resource scope to policy decision",
    "validate target against user relationship",
    "display target in approval",
    "verify exact target after execution"
  ]
}

6B.6 Abuse case — Knowledge poisoning

An attacker modifies a source, uploads a malicious document, alters metadata, or exploits weak ingestion governance. The poisoned content may remain dormant until retrieved for a high-impact task.

StageThreatControl
Source onboardingUnauthorized source becomes trustedOwner approval and source classification
IngestionContent or metadata tamperingIntegrity checks, versioning, provenance
IndexingACL or tenant attributes lostPermission-preserving index pipeline
RetrievalPoisoned content ranks highlyAuthority weighting, diversity, anomaly signals
UseModel treats content as instruction or factEvidence separation, citations, verification

6B.7 Abuse case — Cross-agent propagation

A compromised or manipulated agent passes malicious instructions, false conclusions, or sensitive data to another agent. The receiving agent may possess stronger tools or a different trust level.

Secure handoffs should contain structured results, evidence references, sensitivity labels, and allowed next capabilities. The receiving agent must not inherit the sender’s permissions and should independently evaluate policy.

6B.8 Abuse case — Denial of service and economic exhaustion

  • Recursive planning or agent handoff loops.
  • Oversized documents or repeated multimodal processing.
  • High-cardinality retrieval and ranking.
  • Tool retries against unavailable dependencies.
  • Expensive model routing triggered by crafted prompts.
  • Queue saturation through event replay or duplicate requests.

Controls include quotas, task budgets, maximum context size, timeouts, concurrency limits, circuit breakers, model cost policies, deduplication, and tenant-level isolation.

6B.9 Risk scoring

FactorQuestion
LikelihoodHow accessible is the attack path and how much skill is required?
Business impactCould it cause financial, operational, safety, legal, or reputational harm?
Blast radiusOne record, one tenant, one region, or enterprise-wide?
DetectabilityWould monitoring identify the attack before or after impact?
RecoverabilityCan actions be reversed and evidence reconstructed?
Control maturityAre controls preventive, tested, independent, and automated?

6B.10 Abuse-case checklist

Attack surface includes user, content, model, agent, tools, data, and telemetry.
Indirect prompt injection is modeled as an expected condition.
Data exfiltration paths include outputs, URLs, tools, files, logs, and memory.
Parameter substitution is tested for every high-impact capability.
Knowledge poisoning covers source approval, ingestion, indexing, and retrieval.
Multi-agent handoffs do not transfer authority implicitly.
DoS and economic exhaustion include loops, context size, retries, and model routing.
Each high-risk abuse case has preventive, detective, and recovery controls.

6B.11 Summary

Chapter 6B converts the architectural threat model into concrete abuse cases. It shows how prompt injection, excessive agency, data exfiltration, parameter manipulation, poisoning, propagation, and denial of service can move through the system.

Core conclusion: threat scenarios become actionable only when they identify the complete path from entry point to business impact.