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Security: muchiny/mcp-ssh-bridge

Security

SECURITY.md

Security Policy

Supported Versions

Version Supported
1.8.x Yes
< 1.8 No

Reporting a Vulnerability

If you discover a security vulnerability in MCP SSH Bridge, please report it responsibly.

Do NOT open a public GitHub issue for security vulnerabilities.

How to Report

  1. Email: Send details to the project maintainer (see git log for contact)
  2. GitHub: Use GitHub Security Advisories to report privately

What to Include

  • Description of the vulnerability
  • Steps to reproduce
  • Potential impact
  • Suggested fix (if any)

Response Timeline

  • Acknowledgment: Within 48 hours
  • Initial assessment: Within 1 week
  • Fix and release: Depends on severity
    • Critical: Within 72 hours
    • High: Within 1 week
    • Medium/Low: Next release cycle

Security Model

MCP SSH Bridge acts as a security boundary between an AI client (Claude Code) and remote SSH hosts. See docs/THREAT_MODEL.md for the full threat analysis.

Key Security Controls

Control Description
Command Validation Whitelist/blacklist with regex patterns (CommandValidator)
Shell Escaping Single-quote wrapping for all user-supplied parameters
Output Sanitization 56 patterns masking secrets in command output (Sanitizer)
Rate Limiting Per-host token bucket rate limiter (RateLimiter)
Audit Logging Async JSON-lines audit trail (AuditLogger)
Host Key Verification Strict mode by default (MITM protection)
Memory Safety #![forbid(unsafe_code)], Zeroizing<String> for credentials
Path Validation Traversal prevention on file operations
Dependency Auditing cargo-deny + cargo-audit in CI

Security Modes

  • Strict (default): Only explicitly whitelisted commands are allowed
  • Permissive: All commands except blacklisted patterns

What This Project Does NOT Protect Against

  • Compromise of the MCP client (Claude Code) itself
  • Compromise of the SSH host being connected to
  • Physical access to the machine running the bridge
  • Side-channel attacks on the SSH transport (handled by the SSH library)

There aren’t any published security advisories