CyberRota Analysis
AI-GeneratedThe vulnerability affects the FrontMCP framework and its associated libraries, allowing authenticated users to exploit untrusted OpenAPI specifications to redirect requests to internal services, potentially exposing sensitive administrative APIs and private network endpoints. Organizations utilizing versions 2.3.0 to 2.5.0 of mcp-from-openapi and versions 1.2.1 to 1.5.0 of frontmcp and @frontmcp/adapters should prioritize patching to mitigate the risk of unauthorized access to internal resources. Immediate action is recommended, especially in multi-user deployments where untrusted configurations may be more prevalent.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
FrontMCP is a TypeScript-first framework for the Model Context Protocol (MCP). From mcp-from-openapi 2.3.0 until 2.5.0 and from frontmcp and @frontmcp/adapters 1.2.1 until 1.5.0, libs/adapters/src/openapi/openapi.adapter.ts loadOpenAPISpec() forwards untrusted OpenAPI url and spec inputs and loadOptions.refResolution to OpenAPIToolGenerator.fromURL() and OpenAPIToolGenerator.fromJSON(). The external $ref guard checks parsed hostname strings without resolving addresses, pinning validated addresses, revalidating redirect targets, or normalizing IPv4-mapped IPv6. An authenticated user who can import or configure an OpenAPI specification in a hosted or multi-user deployment can use DNS-to-loopback resolution, redirect-to-loopback behavior, or IPv4-mapped IPv6 loopback forms to cause backend-origin requests to internal services. This can expose internal administrative APIs, metadata-like services, and other private network endpoints. The practical impact is lower when only a trusted local administrator can configure OpenAPI specs, and disabling external reference protocols prevents the external $ref request. This issue is fixed in mcp-from-openapi 2.5.0 and frontmcp and @frontmcp/adapters 1.5.0.