{
 "public_id": "AIR-2025-0026",
 "incident_id": "2025-04-trailofbits-mcp-line-jumping",
 "date_disclosed": "2025-04-21",
 "date_occurred": null,
 "title": "Line jumping: MCP servers can inject prompts through tool descriptions before any tool is invoked",
 "class": "research_demo",
 "attack_surface": "mcp_server",
 "initial_vector": "malicious_tool_description",
 "agent_capability_abused": [
  "tool_description_ingestion",
  "tool_selection"
 ],
 "target_product": "Claude Desktop, Cursor, Cline, Windsurf",
 "target_vendor": "multiple",
 "autonomy_level": "copilot_with_approval",
 "impact_realized": false,
 "impact_type": [
  "agent_hijack",
  "approval_bypass"
 ],
 "blast_radius": "Every MCP client that loads third-party tool descriptions into context",
 "cve": [],
 "taxonomy": {
  "owasp_asi": [
   "ASI01",
   "ASI04"
  ],
  "mitre_atlas": [],
  "labels": [
   "tool_poisoning",
   "mcp",
   "human_in_the_loop_bypass"
  ]
 },
 "defense_present": "Human-in-the-loop tool approval",
 "defense_bypassed": true,
 "fix_shipped": null,
 "primary_sources": [
  "https://blog.trailofbits.com/2025/04/21/jumping-the-line-how-mcp-servers-can-attack-you-before-you-ever-use-them/"
 ],
 "verified_quote": "MCP servers can manipulate model behavior _without ever being invoked_.",
 "confidence": "high",
 "notes": "Trail of Bits' name for what others call tool poisoning. Quote retains the source's markdown emphasis markers. Also: 'This effectively transforms the human-in-the-loop security model into human-as-the-rubber-stamp.'",
 "risk_category": "security_fraud",
 "risk_secondary": [],
 "risk_subcategory": "Tool & Function Call Extraction / Abuse",
 "risk_sub_secondary": [],
 "ai_entity": "generative",
 "agency": "agent_acted",
 "agency_debatable": true,
 "agency_reason": "tool descriptions hijacked the agent before any tool was invoked",
 "vector_family": "malicious_component",
 "vector_detail": "malicious_tool_description",
 "guardrail_kind": [
  "human_approval"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [],
  "cve": [],
  "ghsa": []
 },
 "primary_asi": "ASI01",
 "agent_framework": "unknown",
 "model_provider": "anthropic",
 "model_name": "",
 "detection_mechanism": "external_researcher",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "supply_chain_vulnerabilities",
 "eai_domain": "tool_misuse",
 "eai_secondary": [],
 "eai_reason": "impact rule: supply_chain_vulnerabilities",
 "asi_curated": [
  "ASI01",
  "ASI04"
 ],
 "asi_scope": "in_scope",
 "asi_provenance": "curated",
 "asi_reason": "curated: ASI01,ASI04",
 "submitted_by": "EAI Internal"
}