Fixes #4235

thirdparty/multipart/multipartpost.py

@@ -23,6 +23,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 import io
 import mimetypes
 import os
+import re
 import stat
 import sys
 
@@ -67,6 +68,14 @@ class MultipartPostHandler(_urllib.request.BaseHandler):
                 request.add_unredirected_header("Content-Type", contenttype)
 
             request.data = data
+
+        # NOTE: https://github.com/sqlmapproject/sqlmap/issues/4235
+        if request.data:
+            for match in re.finditer(r"(?i)\s*-{20,}\w+(\s+Content-Disposition[^\n]+\s+|\-\-\s*)", request.data):
+                part = match.group(0)
+                if '\r' not in part:
+                    request.data = request.data.replace(part, part.replace("\n", "\r\n"))
+
         return request
 
     def multipart_encode(self, vars, files, boundary=None, buf=None):