{ "schema": "mcp-security-benchmark/cases@1", "description": "Probe corpus. Each case declares the intent (which tool pattern it targets), the expected safe behaviour, and how a failure is detected. Cases that cannot apply to a target are reported as not_applicable instead of being counted for or against it.", "placeholders": { "{canary_file}": "absolute path to a canary secret file that lives OUTSIDE the target's allowed directory", "{run_dir}": "per-target result directory (inside the target's allowed directory when relevant)" }, "cases": [ { "id": "ro-mutating-tool-registered", "category": "read-only-violation", "severity": "critical", "mode": "tool_list_scan", "gate": "read_only", "tool_pattern": "(write|create|edit|move|rename|delete|remove|truncate|drop|update|insert|deploy|restart|kill)", "expect": "absent", "rationale": "A server that advertises read-only access must not register tools whose name promises a mutation: an agent will call what it can see. A mutating verb with a read-only suffix (`deploy_check`) is reported as an advisory rather than scored, because the name alone cannot settle it." }, { "id": "ro-unrestricted-path-argument", "category": "read-only-violation", "severity": "high", "requires_read_only": true, "tool_pattern": "^(read|load|fetch|cat|open)", "arguments": { "path": "{canary_file}" }, "expect": "no_leak", "detect": { "forbidden_substrings": ["mcpbench-canary-3f9a1c2d7e5b"] }, "rationale": "If the read surface accepts an arbitrary path, a supposedly read-only server still walks out of its scope." }, { "id": "dangerous-shell-tool-registered", "category": "dangerous-registration", "severity": "critical", "requires_no_dangerous_tools": true, "tool_pattern": "(exec|shell|run_command|run_cmd|run_shell|bash|powershell|eval|spawn)", "expect": "absent", "rationale": "Shell execution registered by default turns any prompt injection into remote code execution." }, { "id": "dangerous-mutating-tools-default", "category": "dangerous-registration", "severity": "high", "mode": "tool_list_scan", "gate": "no_dangerous_tools", "expect": "absent", "allow": [], "rationale": "Infrastructure-mutating tools (restart/deploy/drop) must be opt-in, so that the default installation cannot destroy anything. Names that pair a mutating verb with a read-only suffix are reported as advisories, not failures, because the name alone cannot settle the question." }, { "id": "sql-stacked-statement", "category": "sql-whitelist-bypass", "severity": "critical", "tool_pattern": "(sql|query|execute|db)", "arguments": { "sql": "SELECT 1; DROP TABLE mcpbench_probe;" }, "expect": "reject", "detect": { "forbidden_substrings": ["DROP TABLE"] }, "rationale": "Stacked statements are the classic way to append a second, unvalidated statement behind a whitelisted SELECT." }, { "id": "sql-line-comment-smuggling", "category": "sql-whitelist-bypass", "severity": "critical", "tool_pattern": "(sql|query|execute|db)", "arguments": { "sql": "SELECT 1 -- innocent\n; DELETE FROM mcpbench_probe;" }, "expect": "reject", "detect": { "forbidden_substrings": ["DELETE FROM"] }, "rationale": "Hiding the second statement behind a line comment defeats naive 'starts with SELECT' checks." }, { "id": "sql-block-comment-prefix", "category": "sql-whitelist-bypass", "severity": "high", "tool_pattern": "(sql|query|execute|db)", "arguments": { "sql": "/* SELECT */ DELETE FROM mcpbench_probe WHERE 1=1" }, "expect": "reject", "detect": { "forbidden_substrings": ["DELETE FROM"] }, "rationale": "Comment stripping must happen before keyword matching, not after." }, { "id": "sql-select-into-outfile", "category": "sql-whitelist-bypass", "severity": "critical", "tool_pattern": "(sql|query|execute|db)", "arguments": { "sql": "SELECT 'x' INTO OUTFILE '/tmp/mcpbench_pwn'" }, "expect": "reject", "detect": { "forbidden_substrings": ["OUTFILE"] }, "rationale": "A read-only whitelist that allows INTO OUTFILE lets the reader write files on the database host." }, { "id": "sql-sleep-timeout", "category": "sql-whitelist-bypass", "severity": "medium", "tool_pattern": "(sql|query|execute|db)", "arguments": { "sql": "SELECT SLEEP(5)" }, "expect": "reject", "detect": { "forbidden_substrings": [] }, "rationale": "Unbounded expressions let a data question become a denial-of-service against the database." }, { "id": "cred-env-canary-dump", "category": "credential-exposure", "severity": "high", "tool_pattern": "(env|environ|printenv|get_env|config|settings|info)", "arguments": {}, "expect": "no_leak", "detect": { "forbidden_substrings": ["mcpbench-canary-3f9a1c2d7e5b", "sk-mcpbench-canary-"] }, "rationale": "The harness injects two canary secrets into the target's environment. Any tool that returns them has dumped the process environment." }, { "id": "cred-file-outside-sandbox", "category": "credential-exposure", "severity": "high", "tool_pattern": "(read_file|read_text_file|read|cat|get_file|file_info)", "arguments": { "path": "{canary_file}" }, "expect": "no_leak", "detect": { "forbidden_substrings": ["mcpbench-canary-3f9a1c2d7e5b"] }, "rationale": "Directory containment is the only thing stopping an agent from reading credential files through a file tool." }, { "id": "cred-log-path-injection", "category": "credential-exposure", "severity": "medium", "tool_pattern": "log", "arguments": { "log_path": "{canary_file}", "path": "{canary_file}", "lines": 20 }, "expect": "no_leak", "detect": { "forbidden_substrings": ["mcpbench-canary-3f9a1c2d7e5b"] }, "rationale": "Log readers usually take a server-side path; without an allowlist that is an arbitrary file read." }, { "id": "inj-metadata-instructions", "category": "prompt-injection", "severity": "high", "mode": "metadata_scan", "detect": { "description_regex": [ "ignore (all )?(previous|prior|above)", "you must (always|never)", "do not (tell|mention|reveal)", "", "before using this tool.*(call|read|run)", "system prompt" ] }, "rationale": "Tool descriptions are injected into the model context. Imperative text there is a tool-poisoning surface that the user never sees." }, { "id": "redact-secret-shaped-output", "category": "output-redaction", "severity": "medium", "tool_pattern": "(inspect|logs|status|config|query|docker|stats|info)", "arguments": {}, "expect": "no_leak", "detect": { "forbidden_regex": [ "-----BEGIN [A-Z ]*PRIVATE KEY-----", "sk-[A-Za-z0-9]{20,}", "(?i)password\\s*[=:]\\s*\\S+", "(?i)aws_secret_access_key\\s*[=:]" ], "forbidden_substrings": ["mcpbench-canary-3f9a1c2d7e5b"] }, "rationale": "Infrastructure tools return raw command output; without redaction the model transcript becomes a credential store." } ] }