Ledger MCP Server — agentic threat model
The Ledger MCP Server presents a high confidentiality risk by exposing sensitive, plain-text local financial journals to LLMs via MCP tools. Without explicit sandboxing or input sanitization, it is vulnerable to prompt injection attacks leading to unauthorized financial data exfiltration.
OWASP AIVSS score rationale
| Autonomy of Action | 0.20 | |
| Goal-Driven Planning | 0.10 | |
| Self-Modification | 0.00 | |
| Dynamic Tool Use | 0.40 | |
| Persistent Memory | 0.00 | |
| Contextual Awareness | 0.20 | |
| Dynamic Identity | 0.00 | |
| Multi-Agent Interactions | 0.30 | |
| Non-Determinism | 0.20 | |
| Opacity & Reflexivity | 0.30 |
Scored with the canonical OWASP AIVSS formula (AIVSS calculator reference); agentic risk factors estimated from the agent’s described capabilities.
MAESTRO 7-layer threat model
Per-layer threats for this agent. Layers tagged “not certain from listing” are general, caveated commentary where the public description didn’t pin that layer.
Not certain from the listing — The foundation model is not specified as this is an MCP server designed to connect to arbitrary LLM clients; however, the model used will inherit risks of prompt injection and data leakage.
Exposes highly sensitive local plain-text accounting files (personal financial records) to the model. There is a significant risk of data exfiltration or unauthorized knowledge extraction if the model is compromised or manipulated.
Exposes specific ledger-cli query tools (balance, register, report) to the agent framework. If the input arguments to these tools are not strictly sanitized, it could lead to command injection or unauthorized file access on the host system.
Runs locally on the user's machine to access local files. Without explicit containerization or sandboxing, a compromise of the MCP server or the orchestrating agent could lead to local file path traversal and broader host filesystem exposure.
Not certain from the listing — There is no mention of logging, query monitoring, or guardrails to detect anomalous financial queries or data exfiltration attempts.
Not certain from the listing — No authentication, authorization, or access control policies are described to restrict which agents or users can query the sensitive financial ledger.
Operates within the MCP ecosystem, meaning it acts as a tool provider to other agents. A compromised orchestrator agent could abuse this trust relationship to silently harvest and exfiltrate the user's entire financial history.
MAESTRO — the 7-layer agentic threat-modeling framework (Cloud Security Alliance / Ken Huang).