{"id":"GHSA-3ch2-jxxc-v4xf","summary":"@akoskm/create-mcp-server-stdio is vulnerable to MCP Server Command Injection through `exec` API","details":"# Command Injection in MCP Server\n\nThe MCP Server at https://github.com/akoskm/create-mcp-server-stdio is written in a way that is vulnerable to command injection vulnerability attacks as part of some of its MCP Server tool definition and implementation.\n\n## Vulnerable tool\n\nThe MCP Server exposes the tool `which-app-on-port` which relies on Node.js child process API `exec` which is an unsafe and vulnerable API if concatenated with untrusted user input.\n\nVulnerable line of code: https://github.com/akoskm/create-mcp-server-stdio/blob/main/src/index.ts#L24-L40\n\n```js\nserver.tool(\"which-app-on-port\", { port: z.number() }, async ({ port }) =\u003e {\n  const result = await new Promise\u003cProcessInfo\u003e((resolve, reject) =\u003e {\n    exec(`lsof -t -i tcp:${port}`, (error, pidStdout) =\u003e {\n      if (error) {\n        reject(error);\n        return;\n      }\n      const pid = pidStdout.trim();\n      exec(`ps -p ${pid} -o comm=`, (error, stdout) =\u003e {\n        if (error) {\n          reject(error);\n          return;\n        }\n        resolve({ command: stdout.trim(), pid });\n      });\n    });\n  });\n```\n\n## Exploitation\n\nWhen LLMs are tricked through prompt injection (and other techniques and attack vectors) to call the tool with input that uses special shell characters such as `; rm -rf /tmp;#` (be careful actually executing this payload) and other payload variations, the full command-line text will be interepted by the shell and result in other commands except of `ps` executing on the host running the MCP Server.\n\nReference example from prior security research on this topic:\n\n![Cursor defined MCP Server vulnerable to command injection](https://res.cloudinary.com/snyk/image/upload/f_auto,w_2560,q_auto/v1747081395/Screenshot_2025-05-07_at_9.22.11_AM_d76kvm.png)\n\n## Impact\n\nUser initiated and remote command injection on a running MCP Server.\n\n## Recommendation\n\n- Don't use `exec`. Use `execFile` instead, which pins the command and provides the arguments as array elements.\n- If the user input is not a command-line flag, use the `--` notation to terminate command and command-line flag, and indicate that the text after the `--` double dash notation is benign value.\n\n## References and Prior work\n\n1. [Exploiting MCP Servers Vulnerable to Command Injection](https://snyk.io/articles/exploiting-mcp-servers-vulnerable-to-command-injection/)\n2. Liran's [Node.js Secure Coding: Defending Against Command Injection Vulnerabilities](https://www.nodejs-security.com/book/command-injection)\n\n##\n\nDisclosed by [Liran Tal](https://lirantal.com)","aliases":["CVE-2025-54994"],"modified":"2025-09-10T21:03:16Z","published":"2025-09-08T19:42:34Z","database_specific":{"severity":"CRITICAL","github_reviewed":true,"github_reviewed_at":"2025-09-08T19:42:34Z","nvd_published_at":"2025-09-08T20:15:35Z","cwe_ids":["CWE-77","CWE-78"]},"references":[{"type":"WEB","url":"https://github.com/akoskm/create-mcp-server-stdio/security/advisories/GHSA-3ch2-jxxc-v4xf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-54994"},{"type":"WEB","url":"https://github.com/akoskm/create-mcp-server-stdio/pull/1"},{"type":"WEB","url":"https://github.com/akoskm/create-mcp-server-stdio/commit/48c26bbe1f8c62764e4592f33c8300d1cadd2eac"},{"type":"PACKAGE","url":"https://github.com/akoskm/create-mcp-server-stdio"},{"type":"WEB","url":"https://github.com/akoskm/create-mcp-server-stdio/blob/main/src/index.ts#L24-L40"}],"affected":[{"package":{"name":"@akoskm/create-mcp-server-stdio","ecosystem":"npm","purl":"pkg:npm/%40akoskm/create-mcp-server-stdio"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.13"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/09/GHSA-3ch2-jxxc-v4xf/GHSA-3ch2-jxxc-v4xf.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}