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github-actions[bot] edited this page Mar 18, 2026 · 20 revisions

Security

The server includes multiple security layers to prevent misuse while keeping MATLAB accessible to AI agents.

Function Blocklist

By default, these MATLAB functions are blocked:

Function Risk
system() Execute arbitrary OS commands
unix() Execute Unix commands
dos() Execute DOS/Windows commands
! Shell escape operator
eval() Execute arbitrary string as code
feval() Call function by name string
evalc() Evaluate and capture output
evalin() Evaluate in caller/base workspace
assignin() Assign variable in caller/base workspace
perl() Execute Perl scripts
python() Execute Python scripts

Smart Scanning

The security validator strips string literals and comments before checking for blocked functions. This prevents false positives:

% These are SAFE and will NOT trigger the blocklist:
disp('The operating system is great')    % "system" inside a string
% system('ls')                            % "system" inside a comment
msg = "unix-based systems";              % "unix" inside a string

% This WILL be blocked:
system('rm -rf /')                       % Actual system() call

String Literal Processing

The validator processes each line in the following order:

  1. Remove double-quoted strings "..."
  2. Remove single-quoted strings '...' (MATLAB char arrays)
    • A quote preceded by [a-zA-Z0-9_)] is treated as a transpose operator, not a string delimiter
  3. Remove MATLAB comments (% to end of line)

This is a best-effort heuristic without a full MATLAB parser and handles the common cases reliably.

Customizing the Blocklist

security:
  blocked_functions_enabled: true  # Set false to disable entirely
  blocked_functions:               # These are the defaults:
    - "system"
    - "unix"
    - "dos"
    - "!"
    - "eval"
    - "feval"
    - "evalc"
    - "evalin"
    - "assignin"
    - "perl"
    - "python"

Workspace Isolation

When workspace_isolation: true (default), the server runs these commands between sessions:

clear all;
clear global;
clear functions;
fclose all;
restoredefaultpath;

This ensures one user's variables, functions, and file handles don't leak to another user.

Upload Protection

  • Size limit: Configurable via max_upload_size_mb (default 100MB)
  • Filename sanitization: Rejects filenames with:
    • Path traversal sequences (..)
    • Characters outside [a-zA-Z0-9._-]
    • Empty strings
  • Temp directory isolation: Files are uploaded to session-specific temp directories

SSE Transport Security

When using SSE transport for multi-user deployments:

  1. Set require_proxy_auth: true in config — this is a flag that acknowledges you've set up proper authentication
  2. Put the server behind a reverse proxy (nginx, Caddy, Traefik) with authentication
  3. Do NOT expose the SSE port directly to the internet
security:
  require_proxy_auth: true  # Suppresses the security warning

server:
  transport: "sse"
  host: "127.0.0.1"  # Bind to localhost only
  port: 8765

The server logs a warning at startup if SSE is enabled without require_proxy_auth: true.

Session and Resource Cleanup

  • Session timeout: Sessions expire after session_timeout seconds of inactivity (default 3600 seconds / 1 hour)
  • Temp file cleanup: Files are deleted when sessions end (temp_cleanup_on_disconnect: true)
  • Job retention: Completed job metadata is pruned after job_retention_seconds (default 86400 seconds / 24 hours)
  • Maximum sessions: Server supports up to max_sessions concurrent sessions (default 50)

Code Checking

The optional code checker (code_checker.enabled: true) can validate MATLAB code before execution:

  • Auto-check: Enable with auto_check_before_execute: true to automatically validate code before it runs
  • Severity levels: Filter checks by severity (error, warning)
  • Independent of blocklist: The code checker is separate from the function blocklist and can be enabled/disabled independently

Recommendations

Scenario Recommendations
Personal use Default config is fine. stdio transport, basic blocklist
Team server SSE + reverse proxy + auth. Review the default blocklist for your use case. Enable workspace_isolation
Production SSE + reverse proxy + TLS + auth. require_proxy_auth: true. Review blocklist for your use case. Set max_sessions based on capacity. Enable monitoring and logging

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