Open WebUI vulnerable to Server-Side Request Forgery (SSRF) via Arbitrary URL Processing in /api/v1/retrieval/process/web

@@ -2861,6 +2861,26 @@ class BannerModel(BaseModel):
     os.getenv("ENABLE_RAG_LOCAL_WEB_FETCH", "False").lower() == "true"
 )
 
+
+DEFAULT_WEB_FETCH_FILTER_LIST = [
+    "!169.254.169.254",
+    "!fd00:ec2::254",
+    "!metadata.google.internal",
+    "!metadata.azure.com",
+    "!100.100.100.200",
+]
+
+web_fetch_filter_list = os.getenv("WEB_FETCH_FILTER_LIST", "")
+if web_fetch_filter_list == "":
+    web_fetch_filter_list = []
+else:
+    web_fetch_filter_list = [
+        item.strip() for item in web_fetch_filter_list.split(",") if item.strip()
+    ]
+
+WEB_FETCH_FILTER_LIST = list(set(DEFAULT_WEB_FETCH_FILTER_LIST + web_fetch_filter_list))
+
+
 YOUTUBE_LOADER_LANGUAGE = PersistentConfig(
     "YOUTUBE_LOADER_LANGUAGE",
     "rag.youtube_loader_language",

@@ -5,16 +5,13 @@
 
 from pydantic import BaseModel
 
+from open_webui.retrieval.web.utils import is_string_allowed, resolve_hostname
+
 
 def get_filtered_results(results, filter_list):
     if not filter_list:
         return results
 
-    # Domains starting without "!" → allowed
-    allow_list = [d for d in filter_list if not d.startswith("!")]
-    # Domains starting with "!" → blocked
-    block_list = [d[1:] for d in filter_list if d.startswith("!")]
-
     filtered_results = []
 
     for result in results:
@@ -23,17 +20,21 @@ def get_filtered_results(results, filter_list):
             continue
 
         domain = urlparse(url).netloc
+        if not domain:
+            continue
 
-        # If allow list is non-empty, require domain to match one of them
-        if allow_list:
-            if not any(domain.endswith(allowed) for allowed in allow_list):
-                continue
+        hostnames = [domain]
 
-        # Block list always removes matches
-        if any(domain.endswith(blocked) for blocked in block_list):
-            continue
+        try:
+            ipv4_addresses, ipv6_addresses = resolve_hostname(domain)
+            hostnames.extend(ipv4_addresses)
+            hostnames.extend(ipv6_addresses)
+        except Exception:
+            pass
 
-        filtered_results.append(result)
+        if any(is_string_allowed(hostname, filter_list) for hostname in hostnames):
+            filtered_results.append(result)
+            continue
 
     return filtered_results
 

@@ -24,6 +24,7 @@
 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 @@
     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.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,