feat: implement file extension blacklist for upload security (#27540)

api/.env.example

@@ -371,6 +371,12 @@ UPLOAD_IMAGE_FILE_SIZE_LIMIT=10
 UPLOAD_VIDEO_FILE_SIZE_LIMIT=100
 UPLOAD_AUDIO_FILE_SIZE_LIMIT=50
 
+# Comma-separated list of file extensions blocked from upload for security reasons.
+# Extensions should be lowercase without dots (e.g., exe,bat,sh,dll).
+# Empty by default to allow all file types.
+# Recommended: exe,bat,cmd,com,scr,vbs,ps1,msi,dll
+UPLOAD_FILE_EXTENSION_BLACKLIST=
+
 # Model configuration
 MULTIMODAL_SEND_FORMAT=base64
 PROMPT_GENERATION_MAX_TOKENS=512

api/configs/feature/__init__.py

@@ -331,6 +331,31 @@ class FileUploadConfig(BaseSettings):
         default=10,
     )
 
+    inner_UPLOAD_FILE_EXTENSION_BLACKLIST: str = Field(
+        description=(
+            "Comma-separated list of file extensions that are blocked from upload. "
+            "Extensions should be lowercase without dots (e.g., 'exe,bat,sh,dll'). "
+            "Empty by default to allow all file types."
+        ),
+        validation_alias=AliasChoices("UPLOAD_FILE_EXTENSION_BLACKLIST"),
+        default="",
+    )
+
+    @computed_field  # type: ignore[misc]
+    @property
+    def UPLOAD_FILE_EXTENSION_BLACKLIST(self) -> set[str]:
+        """
+        Parse and return the blacklist as a set of lowercase extensions.
+        Returns an empty set if no blacklist is configured.
+        """
+        if not self.inner_UPLOAD_FILE_EXTENSION_BLACKLIST:
+            return set()
+        return {
+            ext.strip().lower().strip(".")
+            for ext in self.inner_UPLOAD_FILE_EXTENSION_BLACKLIST.split(",")
+            if ext.strip()
+        }
+
 
 class HttpConfig(BaseSettings):
     """

api/controllers/common/errors.py

@@ -25,6 +25,12 @@ class UnsupportedFileTypeError(BaseHTTPException):
     code = 415
 
 
+class BlockedFileExtensionError(BaseHTTPException):
+    error_code = "file_extension_blocked"
+    description = "The file extension is blocked for security reasons."
+    code = 400
+
+
 class TooManyFilesError(BaseHTTPException):
     error_code = "too_many_files"
     description = "Only one file is allowed."

api/controllers/console/files.py

@@ -8,6 +8,7 @@ import services
 from configs import dify_config
 from constants import DOCUMENT_EXTENSIONS
 from controllers.common.errors import (
+    BlockedFileExtensionError,
     FilenameNotExistsError,
     FileTooLargeError,
     NoFileUploadedError,
@@ -83,6 +84,8 @@ class FileApi(Resource):
             raise FileTooLargeError(file_too_large_error.description)
         except services.errors.file.UnsupportedFileTypeError:
             raise UnsupportedFileTypeError()
+        except services.errors.file.BlockedFileExtensionError as blocked_extension_error:
+            raise BlockedFileExtensionError(blocked_extension_error.description)
 
         return upload_file, 201
 

api/services/errors/file.py

@@ -11,3 +11,7 @@ class FileTooLargeError(BaseServiceError):
 
 class UnsupportedFileTypeError(BaseServiceError):
     pass
+
+
+class BlockedFileExtensionError(BaseServiceError):
+    description = "File extension '{extension}' is not allowed for security reasons"

api/services/file_service.py

@@ -23,7 +23,7 @@ from models import Account
 from models.enums import CreatorUserRole
 from models.model import EndUser, UploadFile
 
-from .errors.file import FileTooLargeError, UnsupportedFileTypeError
+from .errors.file import BlockedFileExtensionError, FileTooLargeError, UnsupportedFileTypeError
 
 PREVIEW_WORDS_LIMIT = 3000
 
@@ -59,6 +59,10 @@ class FileService:
         if len(filename) > 200:
             filename = filename.split(".")[0][:200] + "." + extension
 
+        # check if extension is in blacklist
+        if extension and extension in dify_config.UPLOAD_FILE_EXTENSION_BLACKLIST:
+            raise BlockedFileExtensionError(f"File extension '.{extension}' is not allowed for security reasons")
+
         if source == "datasets" and extension not in DOCUMENT_EXTENSIONS:
             raise UnsupportedFileTypeError()
 

api/tests/test_containers_integration_tests/services/test_file_service.py

@@ -11,7 +11,7 @@ from configs import dify_config
 from models import Account, Tenant
 from models.enums import CreatorUserRole
 from models.model import EndUser, UploadFile
-from services.errors.file import FileTooLargeError, UnsupportedFileTypeError
+from services.errors.file import BlockedFileExtensionError, FileTooLargeError, UnsupportedFileTypeError
 from services.file_service import FileService
 
 
@@ -943,3 +943,150 @@ class TestFileService:
 
         # Should have the signed URL when source_url is empty
         assert upload_file2.source_url == "https://example.com/signed-url"
+
+    # Test file extension blacklist
+    def test_upload_file_blocked_extension(
+        self, db_session_with_containers, engine, mock_external_service_dependencies
+    ):
+        """
+        Test file upload with blocked extension.
+        """
+        fake = Faker()
+        account = self._create_test_account(db_session_with_containers, mock_external_service_dependencies)
+
+        # Mock blacklist configuration by patching the inner field
+        with patch.object(dify_config, "inner_UPLOAD_FILE_EXTENSION_BLACKLIST", "exe,bat,sh"):
+            filename = "malware.exe"
+            content = b"test content"
+            mimetype = "application/x-msdownload"
+
+            with pytest.raises(BlockedFileExtensionError):
+                FileService(engine).upload_file(
+                    filename=filename,
+                    content=content,
+                    mimetype=mimetype,
+                    user=account,
+                )
+
+    def test_upload_file_blocked_extension_case_insensitive(
+        self, db_session_with_containers, engine, mock_external_service_dependencies
+    ):
+        """
+        Test file upload with blocked extension (case insensitive).
+        """
+        fake = Faker()
+        account = self._create_test_account(db_session_with_containers, mock_external_service_dependencies)
+
+        # Mock blacklist configuration by patching the inner field
+        with patch.object(dify_config, "inner_UPLOAD_FILE_EXTENSION_BLACKLIST", "exe,bat"):
+            # Test with uppercase extension
+            filename = "malware.EXE"
+            content = b"test content"
+            mimetype = "application/x-msdownload"
+
+            with pytest.raises(BlockedFileExtensionError):
+                FileService(engine).upload_file(
+                    filename=filename,
+                    content=content,
+                    mimetype=mimetype,
+                    user=account,
+                )
+
+    def test_upload_file_not_in_blacklist(self, db_session_with_containers, engine, mock_external_service_dependencies):
+        """
+        Test file upload with extension not in blacklist.
+        """
+        fake = Faker()
+        account = self._create_test_account(db_session_with_containers, mock_external_service_dependencies)
+
+        # Mock blacklist configuration by patching the inner field
+        with patch.object(dify_config, "inner_UPLOAD_FILE_EXTENSION_BLACKLIST", "exe,bat,sh"):
+            filename = "document.pdf"
+            content = b"test content"
+            mimetype = "application/pdf"
+
+            upload_file = FileService(engine).upload_file(
+                filename=filename,
+                content=content,
+                mimetype=mimetype,
+                user=account,
+            )
+
+            assert upload_file is not None
+            assert upload_file.name == filename
+            assert upload_file.extension == "pdf"
+
+    def test_upload_file_empty_blacklist(self, db_session_with_containers, engine, mock_external_service_dependencies):
+        """
+        Test file upload with empty blacklist (default behavior).
+        """
+        fake = Faker()
+        account = self._create_test_account(db_session_with_containers, mock_external_service_dependencies)
+
+        # Mock empty blacklist configuration by patching the inner field
+        with patch.object(dify_config, "inner_UPLOAD_FILE_EXTENSION_BLACKLIST", ""):
+            # Should allow all file types when blacklist is empty
+            filename = "script.sh"
+            content = b"#!/bin/bash\necho test"
+            mimetype = "application/x-sh"
+
+            upload_file = FileService(engine).upload_file(
+                filename=filename,
+                content=content,
+                mimetype=mimetype,
+                user=account,
+            )
+
+            assert upload_file is not None
+            assert upload_file.extension == "sh"
+
+    def test_upload_file_multiple_blocked_extensions(
+        self, db_session_with_containers, engine, mock_external_service_dependencies
+    ):
+        """
+        Test file upload with multiple blocked extensions.
+        """
+        fake = Faker()
+        account = self._create_test_account(db_session_with_containers, mock_external_service_dependencies)
+
+        # Mock blacklist with multiple extensions by patching the inner field
+        blacklist_str = "exe,bat,cmd,com,scr,vbs,ps1,msi,dll"
+        with patch.object(dify_config, "inner_UPLOAD_FILE_EXTENSION_BLACKLIST", blacklist_str):
+            for ext in blacklist_str.split(","):
+                filename = f"malware.{ext}"
+                content = b"test content"
+                mimetype = "application/octet-stream"
+
+                with pytest.raises(BlockedFileExtensionError):
+                    FileService(engine).upload_file(
+                        filename=filename,
+                        content=content,
+                        mimetype=mimetype,
+                        user=account,
+                    )
+
+    def test_upload_file_no_extension_with_blacklist(
+        self, db_session_with_containers, engine, mock_external_service_dependencies
+    ):
+        """
+        Test file upload with no extension when blacklist is configured.
+        """
+        fake = Faker()
+        account = self._create_test_account(db_session_with_containers, mock_external_service_dependencies)
+
+        # Mock blacklist configuration by patching the inner field
+        with patch.object(dify_config, "inner_UPLOAD_FILE_EXTENSION_BLACKLIST", "exe,bat"):
+            # Files with no extension should not be blocked
+            filename = "README"
+            content = b"test content"
+            mimetype = "text/plain"
+
+            upload_file = FileService(engine).upload_file(
+                filename=filename,
+                content=content,
+                mimetype=mimetype,
+                user=account,
+            )
+
+            assert upload_file is not None
+            assert upload_file.extension == ""

docker/.env.example

@@ -762,6 +762,12 @@ UPLOAD_FILE_SIZE_LIMIT=15
 # The maximum number of files that can be uploaded at a time, default 5.
 UPLOAD_FILE_BATCH_LIMIT=5
 
+# Comma-separated list of file extensions blocked from upload for security reasons.
+# Extensions should be lowercase without dots (e.g., exe,bat,sh,dll).
+# Empty by default to allow all file types.
+# Recommended: exe,bat,cmd,com,scr,vbs,ps1,msi,dll
+UPLOAD_FILE_EXTENSION_BLACKLIST=
+
 # ETL type, support: `dify`, `Unstructured`
 # `dify` Dify's proprietary file extraction scheme
 # `Unstructured` Unstructured.io file extraction scheme

docker/docker-compose.yaml

@@ -353,6 +353,7 @@ x-shared-env: &shared-api-worker-env
   CLICKZETTA_VECTOR_DISTANCE_FUNCTION: ${CLICKZETTA_VECTOR_DISTANCE_FUNCTION:-cosine_distance}
   UPLOAD_FILE_SIZE_LIMIT: ${UPLOAD_FILE_SIZE_LIMIT:-15}
   UPLOAD_FILE_BATCH_LIMIT: ${UPLOAD_FILE_BATCH_LIMIT:-5}
+  UPLOAD_FILE_EXTENSION_BLACKLIST: ${UPLOAD_FILE_EXTENSION_BLACKLIST:-}
   ETL_TYPE: ${ETL_TYPE:-dify}
   UNSTRUCTURED_API_URL: ${UNSTRUCTURED_API_URL:-}
   UNSTRUCTURED_API_KEY: ${UNSTRUCTURED_API_KEY:-}

web/app/components/base/file-uploader/hooks.ts

@@ -11,6 +11,7 @@ import type { FileEntity } from './types'
 import { useFileStore } from './store'
 import {
   fileUpload,
+  getFileUploadErrorMessage,
   getSupportFileType,
   isAllowedFileExtension,
 } from './utils'
@@ -172,8 +173,9 @@ export const useFile = (fileConfig: FileUpload) => {
         onSuccessCallback: (res) => {
           handleUpdateFile({ ...uploadingFile, uploadedId: res.id, progress: 100 })
         },
-        onErrorCallback: () => {
+        onErrorCallback: (error?: any) => {
-          notify({ type: 'error', message: t('common.fileUploader.uploadFromComputerUploadError') })
+          const errorMessage = getFileUploadErrorMessage(error, t('common.fileUploader.uploadFromComputerUploadError'), t)
+          notify({ type: 'error', message: errorMessage })
           handleUpdateFile({ ...uploadingFile, progress: -1 })
         },
       }, !!params.token)
@@ -279,8 +281,9 @@ export const useFile = (fileConfig: FileUpload) => {
           onSuccessCallback: (res) => {
             handleUpdateFile({ ...uploadingFile, uploadedId: res.id, progress: 100 })
           },
-          onErrorCallback: () => {
+          onErrorCallback: (error?: any) => {
-            notify({ type: 'error', message: t('common.fileUploader.uploadFromComputerUploadError') })
+            const errorMessage = getFileUploadErrorMessage(error, t('common.fileUploader.uploadFromComputerUploadError'), t)
+            notify({ type: 'error', message: errorMessage })
             handleUpdateFile({ ...uploadingFile, progress: -1 })
           },
         }, !!params.token)

web/app/components/base/file-uploader/utils.ts

@@ -7,11 +7,30 @@ import { SupportUploadFileTypes } from '@/app/components/workflow/types'
 import type { FileResponse } from '@/types/workflow'
 import { TransferMethod } from '@/types/app'
 
+/**
+ * Get appropriate error message for file upload errors
+ * @param error - The error object from upload failure
+ * @param defaultMessage - Default error message to use if no specific error is matched
+ * @param t - Translation function
+ * @returns Localized error message
+ */
+export const getFileUploadErrorMessage = (error: any, defaultMessage: string, t: (key: string) => string): string => {
+  const errorCode = error?.response?.code
+
+  if (errorCode === 'forbidden')
+    return error?.response?.message
+
+  if (errorCode === 'file_extension_blocked')
+    return t('common.fileUploader.fileExtensionBlocked')
+
+  return defaultMessage
+}
+
 type FileUploadParams = {
   file: File
   onProgressCallback: (progress: number) => void
   onSuccessCallback: (res: { id: string }) => void
-  onErrorCallback: () => void
+  onErrorCallback: (error?: any) => void
 }
 type FileUpload = (v: FileUploadParams, isPublic?: boolean, url?: string) => void
 export const fileUpload: FileUpload = ({
@@ -37,8 +56,8 @@ export const fileUpload: FileUpload = ({
     .then((res: { id: string }) => {
       onSuccessCallback(res)
     })
-    .catch(() => {
+    .catch((error) => {
-      onErrorCallback()
+      onErrorCallback(error)
     })
 }
 

web/app/components/base/image-uploader/hooks.ts

@@ -2,7 +2,7 @@ import { useCallback, useMemo, useRef, useState } from 'react'
 import type { ClipboardEvent } from 'react'
 import { useParams } from 'next/navigation'
 import { useTranslation } from 'react-i18next'
-import { imageUpload } from './utils'
+import { getImageUploadErrorMessage, imageUpload } from './utils'
 import { useToastContext } from '@/app/components/base/toast'
 import { ALLOW_FILE_EXTENSIONS, TransferMethod } from '@/types/app'
 import type { ImageFile, VisionSettings } from '@/types/app'
@@ -81,8 +81,9 @@ export const useImageFiles = () => {
           filesRef.current = newFiles
           setFiles(newFiles)
         },
-        onErrorCallback: () => {
+        onErrorCallback: (error?: any) => {
-          notify({ type: 'error', message: t('common.imageUploader.uploadFromComputerUploadError') })
+          const errorMessage = getImageUploadErrorMessage(error, t('common.imageUploader.uploadFromComputerUploadError'), t)
+          notify({ type: 'error', message: errorMessage })
           const newFiles = [...files.slice(0, index), { ...currentImageFile, progress: -1 }, ...files.slice(index + 1)]
           filesRef.current = newFiles
           setFiles(newFiles)
@@ -158,8 +159,9 @@ export const useLocalFileUploader = ({ limit, disabled = false, onUpload }: useL
           onSuccessCallback: (res) => {
             onUpload({ ...imageFile, fileId: res.id, progress: 100 })
           },
-          onErrorCallback: () => {
+          onErrorCallback: (error?: any) => {
-            notify({ type: 'error', message: t('common.imageUploader.uploadFromComputerUploadError') })
+            const errorMessage = getImageUploadErrorMessage(error, t('common.imageUploader.uploadFromComputerUploadError'), t)
+            notify({ type: 'error', message: errorMessage })
             onUpload({ ...imageFile, progress: -1 })
           },
         }, !!params.token)

web/app/components/base/image-uploader/utils.ts

@@ -1,10 +1,29 @@
 import { upload } from '@/service/base'
 
+/**
+ * Get appropriate error message for image upload errors
+ * @param error - The error object from upload failure
+ * @param defaultMessage - Default error message to use if no specific error is matched
+ * @param t - Translation function
+ * @returns Localized error message
+ */
+export const getImageUploadErrorMessage = (error: any, defaultMessage: string, t: (key: string) => string): string => {
+  const errorCode = error?.response?.code
+
+  if (errorCode === 'forbidden')
+    return error?.response?.message
+
+  if (errorCode === 'file_extension_blocked')
+    return t('common.fileUploader.fileExtensionBlocked')
+
+  return defaultMessage
+}
+
 type ImageUploadParams = {
   file: File
   onProgressCallback: (progress: number) => void
   onSuccessCallback: (res: { id: string }) => void
-  onErrorCallback: () => void
+  onErrorCallback: (error?: any) => void
 }
 type ImageUpload = (v: ImageUploadParams, isPublic?: boolean, url?: string) => void
 export const imageUpload: ImageUpload = ({
@@ -30,7 +49,7 @@ export const imageUpload: ImageUpload = ({
     .then((res: { id: string }) => {
       onSuccessCallback(res)
     })
-    .catch(() => {
+    .catch((error) => {
-      onErrorCallback()
+      onErrorCallback(error)
     })
 }

web/app/components/custom/custom-web-app-brand/index.tsx

@@ -16,7 +16,7 @@ import Button from '@/app/components/base/button'
 import Divider from '@/app/components/base/divider'
 import { useProviderContext } from '@/context/provider-context'
 import { Plan } from '@/app/components/billing/type'
-import { imageUpload } from '@/app/components/base/image-uploader/utils'
+import { getImageUploadErrorMessage, imageUpload } from '@/app/components/base/image-uploader/utils'
 import { useToastContext } from '@/app/components/base/toast'
 import { BubbleTextMod } from '@/app/components/base/icons/src/vender/solid/communication'
 import {
@@ -67,8 +67,9 @@ const CustomWebAppBrand = () => {
         setUploadProgress(100)
         setFileId(res.id)
       },
-      onErrorCallback: () => {
+      onErrorCallback: (error?: any) => {
-        notify({ type: 'error', message: t('common.imageUploader.uploadFromComputerUploadError') })
+        const errorMessage = getImageUploadErrorMessage(error, t('common.imageUploader.uploadFromComputerUploadError'), t)
+        notify({ type: 'error', message: errorMessage })
         setUploadProgress(-1)
       },
     }, false, '/workspaces/custom-config/webapp-logo/upload')

web/app/components/datasets/create/file-uploader/index.tsx

@@ -18,6 +18,7 @@ import { LanguagesSupported } from '@/i18n-config/language'
 import { IS_CE_EDITION } from '@/config'
 import { Theme } from '@/types/app'
 import useTheme from '@/hooks/use-theme'
+import { getFileUploadErrorMessage } from '@/app/components/base/file-uploader/utils'
 
 type IFileUploaderProps = {
   fileList: FileItem[]
@@ -134,7 +135,8 @@ const FileUploader = ({
         return Promise.resolve({ ...completeFile })
       })
       .catch((e) => {
-        notify({ type: 'error', message: e?.response?.code === 'forbidden' ? e?.response?.message : t('datasetCreation.stepOne.uploader.failed') })
+        const errorMessage = getFileUploadErrorMessage(e, t('datasetCreation.stepOne.uploader.failed'), t)
+        notify({ type: 'error', message: errorMessage })
         onFileUpdate(fileItem, -2, fileListRef.current)
         return Promise.resolve({ ...fileItem })
       })

web/app/components/datasets/documents/create-from-pipeline/data-source/local-file/index.tsx

@@ -8,6 +8,7 @@ import cn from '@/utils/classnames'
 import type { CustomFile as File, FileItem } from '@/models/datasets'
 import { ToastContext } from '@/app/components/base/toast'
 import { upload } from '@/service/base'
+import { getFileUploadErrorMessage } from '@/app/components/base/file-uploader/utils'
 import I18n from '@/context/i18n'
 import { LanguagesSupported } from '@/i18n-config/language'
 import { IS_CE_EDITION } from '@/config'
@@ -154,7 +155,8 @@ const LocalFile = ({
         return Promise.resolve({ ...completeFile })
       })
       .catch((e) => {
-        notify({ type: 'error', message: e?.response?.code === 'forbidden' ? e?.response?.message : t('datasetCreation.stepOne.uploader.failed') })
+        const errorMessage = getFileUploadErrorMessage(e, t('datasetCreation.stepOne.uploader.failed'), t)
+        notify({ type: 'error', message: errorMessage })
         updateFile(fileItem, -2, fileListRef.current)
         return Promise.resolve({ ...fileItem })
       })

web/app/components/datasets/documents/detail/batch-modal/csv-uploader.tsx

@@ -12,6 +12,7 @@ import { ToastContext } from '@/app/components/base/toast'
 import Button from '@/app/components/base/button'
 import type { FileItem } from '@/models/datasets'
 import { upload } from '@/service/base'
+import { getFileUploadErrorMessage } from '@/app/components/base/file-uploader/utils'
 import useSWR from 'swr'
 import { fetchFileUploadConfig } from '@/service/common'
 import SimplePieChart from '@/app/components/base/simple-pie-chart'
@@ -74,7 +75,8 @@ const CSVUploader: FC<Props> = ({
         return Promise.resolve({ ...completeFile })
       })
       .catch((e) => {
-        notify({ type: 'error', message: e?.response?.code === 'forbidden' ? e?.response?.message : t('datasetCreation.stepOne.uploader.failed') })
+        const errorMessage = getFileUploadErrorMessage(e, t('datasetCreation.stepOne.uploader.failed'), t)
+        notify({ type: 'error', message: errorMessage })
         const errorFile = {
           ...fileItem,
           progress: -2,

web/i18n/en-US/common.ts

@@ -734,6 +734,7 @@ const translation = {
     uploadFromComputerLimit: 'Upload {{type}} cannot exceed {{size}}',
     pasteFileLinkInvalid: 'Invalid file link',
     fileExtensionNotSupport: 'File extension not supported',
+    fileExtensionBlocked: 'This file type is blocked for security reasons',
   },
   tag: {
     placeholder: 'All Tags',

web/i18n/zh-Hans/common.ts

@@ -728,6 +728,7 @@ const translation = {
     uploadFromComputerLimit: '上传 {{type}} 不能超过 {{size}}',
     pasteFileLinkInvalid: '文件链接无效',
     fileExtensionNotSupport: '文件类型不支持',
+    fileExtensionBlocked: '出于安全考虑，该文件类型已被禁止上传',
   },
   tag: {
     placeholder: '全部标签',