bpo-38243, xmlrpc.server: Escape the server_title (GH-16373)

Escape the server title of xmlrpc.server.DocXMLRPCServer
when rendering the document page as HTML.

Lib/test/test_docxmlrpc.py

 from xmlrpc.server import DocXMLRPCServer
 import http.client
+import re
 import sys
 import threading
 import unittest
@@ -192,6 +193,21 @@ class DocXMLRPCHTTPGETServer(unittest.TestCase):
              b'method_annotation</strong></a>(x: bytes)</dt></dl>'),
             response.read())
 
+    def test_server_title_escape(self):
+        # bpo-38243: Ensure that the server title and documentation
+        # are escaped for HTML.
+        self.serv.set_server_title('test_title<script>')
+        self.serv.set_server_documentation('test_documentation<script>')
+        self.assertEqual('test_title<script>', self.serv.server_title)
+        self.assertEqual('test_documentation<script>',
+                self.serv.server_documentation)
+
+        generated = self.serv.generate_html_documentation()
+        title = re.search(r'<title>(.+?)</title>', generated).group()
+        documentation = re.search(r'<p><tt>(.+?)</tt></p>', generated).group()
+        self.assertEqual('<title>Python: test_title&lt;script&gt;</title>', title)
+        self.assertEqual('<p><tt>test_documentation&lt;script&gt;</tt></p>', documentation)
+
 
 if __name__ == '__main__':
     unittest.main()

Lib/xmlrpc/server.py

@@ -108,6 +108,7 @@ from xmlrpc.client import Fault, dumps, loads, gzip_encode, gzip_decode
 from http.server import BaseHTTPRequestHandler
 from functools import partial
 from inspect import signature
+import html
 import http.server
 import socketserver
 import sys
@@ -894,7 +895,7 @@ class XMLRPCDocGenerator:
                                 methods
                             )
 
-        return documenter.page(self.server_title, documentation)
+        return documenter.page(html.escape(self.server_title), documentation)
 
 class DocXMLRPCRequestHandler(SimpleXMLRPCRequestHandler):
     """XML-RPC and documentation request handler class.

Misc/NEWS.d/next/Security/2019-09-25-13-21-09.bpo-38243.1pfz24.rst

+Escape the server title of :class:`xmlrpc.server.DocXMLRPCServer`
+when rendering the document page as HTML.
+(Contributed by Dong-hee Na in :issue:`38243`.)