Add test to verify vncserver TCP port isn't open

Author: consideRatio

tests/test_browser.py

@@ -1,3 +1,4 @@
+import socket
 from os import getenv
 from pathlib import Path
 from shutil import which
@@ -38,6 +39,22 @@ def compare_screenshot(test_image):
     assert m < threshold
 
 
+def assert_no_vncserver_tcp_port_open(host="localhost", port=5901, timeout=1):
+    """
+    Test that a specific port is not open, which would be a security issue.
+    Returns:
+        True if the port is closed (secure), False if open (security issue)
+    """
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock.settimeout(timeout)
+    result = sock.connect_ex((host, port))
+    sock.close()
+    
+    # If result is 0, connection was successful (port is open - security issue)
+    # Otherwise, connection failed (port is closed - secure)
+    assert result != 0
+
+
 # To debug this set environment variable HEADLESS=0
 def test_desktop(browser):
     page = browser
@@ -54,6 +71,8 @@ def test_desktop(browser):
     expect(page1.get_by_text("Status: Connected")).to_be_visible()
     expect(page1.locator("canvas")).to_be_visible()
 
+    assert_no_vncserver_tcp_port_open()
+
     # Screenshot the desktop element only
     # May take a few seconds to load
     page1.wait_for_timeout(5000)