Merge pull request #807 from christianlouis/sentinel-fix-ssrf-dns-resolution-16520734505214840647

🛡️ Sentinel: [HIGH] Fix SSRF bypass on DNS resolution failure

app/utils/network.py

@@ -27,8 +27,8 @@ def is_private_ip(hostname: str) -> bool:
                     return True
             return False
         except (socket.gaierror, socket.error):
-            # Cannot resolve - allow for testing/development
-            # In production, DNS should work properly
-            # Log this for debugging
-            logger.warning(f"Could not resolve hostname: {hostname}")
-            return False  # Changed from True to False to allow external domains in tests
+            # Cannot resolve.
+            # Fail securely: block unresolved domains to prevent DNS rebinding
+            # and SSRF bypasses via unresolvable addresses.
+            logger.warning(f"Could not resolve hostname (blocking securely): {hostname}")
+            return True