GHSA-27m7-ffhq-jqrm

### Summary The `MCPScanner ` class contains a critical Command Injection vulnerability in the `cloneRepo `method. The application passes the user-supplied githubUrl argument directly to a system shell via execSync without sanitization. This allows an attacker to execute arbitrary commands on the host machine by appending shell metacharacters to the URL. ### Details The vulnerability exists in the src/scanner/MCPScanner.ts file within the cloneRepo method. [https://github.com/kapilduraphe/mcp-watch/blob/0fca7228bd313ae5aa938d61311377e88ce6e682/src/scanner/McpScanner.ts#L181](https://github.com/kapilduraphe/mcp-watch/blob/0fca7228bd313ae5aa938d61311377e88ce6e682/src/scanner/McpScanner.ts#L181) The code uses child_process.execSync to execute a git clone command: Because execSync spawns a shell (defaulting to `/bin/sh` on Unix or` cmd.exe` on Windows), any shell metacharacters present in the url argument will be interpreted by the shell. The application does not validate that the url is a valid Git URL, nor does it sanitize input for shell metacharacters. ### PoC Install the package or clone the repository. Run the scanner using the CLI (or invoke scanRepository programmatically). Provide a malicious URL containing a command separator (e.g., ;, &, or |) and a system command. payload : `npm run scan:github "https://github.com/kapilduraphe/mcp-watch & calc.exe"` <img width="1918" height="1046" alt="image" src="https://github.com/user-attachments/assets/021c1dfa-3f87-483c-aecb-6939bcf9c925" /> ### Impact Severity: **Critical** **CVSS Score**: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) Description: This vulnerability allows an attacker to execute arbitrary code on the machine running the scanner. If run by a developer locally, it compromises their workstation. If deployed as a hosted scanning service, it grants the attacker full control over the server (RCE), leading to potential data exfiltration, service disruption, or further lateral movement within the infrastructure. **Context Dependent Risk:** Local CLI : If you run this tool locally on your own machine, you are "hacking yourself." The risk is limited unless you copy-paste a malicious URL sent by someone else (e.g., "Hey, check this repo scan: npm run scan "https://git./..; rm -rf /"). **Web Service / CI Pipeline (Critical Risk)**: If this scanner is deployed as a web service (e.g., "Paste your repo URL to scan"), an attacker can take full control of the server immediately.