mcp-builder
Fail
Audited by Gen Agent Trust Hub on Feb 16, 2026
Risk Level: HIGHCOMMAND_EXECUTIONREMOTE_CODE_EXECUTIONEXTERNAL_DOWNLOADSPROMPT_INJECTION
Full Analysis
- [COMMAND_EXECUTION] (HIGH): The file
scripts/connections.pyimplements theMCPConnectionStdioclass which wrapsmcp.client.stdio.stdio_client. This class accepts acommandandargsparameter from the caller and executes it as a subprocess on the host system. - [REMOTE_CODE_EXECUTION] (HIGH): The skill instructions in
SKILL.md(Phase 3.2) guide the agent to perform build and test operations using shell commands such asnpm run buildandnpx @modelcontextprotocol/inspector. When these parameters are derived from external documentation found during Phase 1, it enables an RCE path. - [EXTERNAL_DOWNLOADS] (LOW): The skill directs the agent to fetch content from
modelcontextprotocol.ioandraw.githubusercontent.com. While these are considered trusted sources under [TRUST-SCOPE-RULE] for the download itself, the content ingested directly influences high-privilege operations (command execution). - [PROMPT_INJECTION] (HIGH): The skill has a significant indirect prompt injection surface. Ingestion points: Uses WebFetch to read external API docs and GitHub READMEs (SKILL.md). Boundary markers: Absent; there are no instructions to help the agent distinguish between hard protocols and instructions found in external data. Capability inventory: Command execution via
scripts/connections.pyand direct shell usage. Sanitization: Absent; the skill lacks any validation or filtering of external content before use in configuration or execution.
Recommendations
- AI detected serious security threats
Audit Metadata