feat/security: Add SSRF protection with configurable blocklist

Co-Authored-By: Classic298 <27028174+Classic298@users.noreply.github.com>

backend/open_webui/retrieval/web/utils.py

@@ -24,6 +24,7 @@ import validators
 from langchain_community.document_loaders import PlaywrightURLLoader, WebBaseLoader
 from langchain_community.document_loaders.base import BaseLoader
 from langchain_core.documents import Document
+
 from open_webui.retrieval.loaders.tavily import TavilyLoader
 from open_webui.retrieval.loaders.external_web import ExternalWebLoader
 from open_webui.constants import ERROR_MESSAGES
@@ -38,6 +39,7 @@ from open_webui.config import (
     TAVILY_EXTRACT_DEPTH,
     EXTERNAL_WEB_LOADER_URL,
     EXTERNAL_WEB_LOADER_API_KEY,
+    WEB_FETCH_FILTER_LIST,
 )
 from open_webui.env import SRC_LOG_LEVELS
 
@@ -46,10 +48,71 @@ log = logging.getLogger(__name__)
 log.setLevel(SRC_LOG_LEVELS["RAG"])
 
 
+def resolve_hostname(hostname):
+    # Get address information
+    addr_info = socket.getaddrinfo(hostname, None)
+
+    # Extract IP addresses from address information
+    ipv4_addresses = [info[4][0] for info in addr_info if info[0] == socket.AF_INET]
+    ipv6_addresses = [info[4][0] for info in addr_info if info[0] == socket.AF_INET6]
+
+    return ipv4_addresses, ipv6_addresses
+
+
+def get_allow_block_lists(filter_list):
+    allow_list = []
+    block_list = []
+
+    if filter_list:
+        for d in filter_list:
+            if d.startswith("!"):
+                # Domains starting with "!" → blocked
+                block_list.append(d[1:])
+            else:
+                # Domains starting without "!" → allowed
+                allow_list.append(d)
+
+    return allow_list, block_list
+
+
+def is_string_allowed(string: str, filter_list: Optional[list[str]] = None) -> bool:
+    if not filter_list:
+        return True
+
+    allow_list, block_list = get_allow_block_lists(filter_list)
+    # If allow list is non-empty, require domain to match one of them
+    if allow_list:
+        if not any(string.endswith(allowed) for allowed in allow_list):
+            return False
+
+    # Block list always removes matches
+    if any(string.endswith(blocked) for blocked in block_list):
+        return False
+
+    return True
+
+
 def validate_url(url: Union[str, Sequence[str]]):
     if isinstance(url, str):
         if isinstance(validators.url(url), validators.ValidationError):
             raise ValueError(ERROR_MESSAGES.INVALID_URL)
+
+        parsed_url = urllib.parse.urlparse(url)
+
+        # Protocol validation - only allow http/https
+        if parsed_url.scheme not in ["http", "https"]:
+            log.warning(
+                f"Blocked non-HTTP(S) protocol: {parsed_url.scheme} in URL: {url}"
+            )
+            raise ValueError(ERROR_MESSAGES.INVALID_URL)
+
+        # Blocklist check using unified filtering logic
+        if WEB_FETCH_FILTER_LIST:
+            result = is_string_allowed(url, WEB_FETCH_FILTER_LIST)
+            if len(result) == 0:
+                log.warning(f"URL blocked by filter list: {url}")
+                raise ValueError(ERROR_MESSAGES.INVALID_URL)
+
         if not ENABLE_RAG_LOCAL_WEB_FETCH:
             # Local web fetch is disabled, filter out any URLs that resolve to private IP addresses
             parsed_url = urllib.parse.urlparse(url)
@@ -82,17 +145,6 @@ def safe_validate_urls(url: Sequence[str]) -> Sequence[str]:
     return valid_urls
 
 
-def resolve_hostname(hostname):
-    # Get address information
-    addr_info = socket.getaddrinfo(hostname, None)
-
-    # Extract IP addresses from address information
-    ipv4_addresses = [info[4][0] for info in addr_info if info[0] == socket.AF_INET]
-    ipv6_addresses = [info[4][0] for info in addr_info if info[0] == socket.AF_INET6]
-
-    return ipv4_addresses, ipv6_addresses
-
-
 def extract_metadata(soup, url):
     metadata = {"source": url}
     if title := soup.find("title"):
@@ -642,6 +694,10 @@ def get_web_loader(
     # Check if the URLs are valid
     safe_urls = safe_validate_urls([urls] if isinstance(urls, str) else urls)
 
+    if not safe_urls:
+        log.warning(f"All provided URLs were blocked or invalid: {urls}")
+        raise ValueError(ERROR_MESSAGES.INVALID_URL)
+
     web_loader_args = {
         "web_paths": safe_urls,
         "verify_ssl": verify_ssl,