[Python-checkins] bpo-42988: Remove the pydoc getfile feature (GH-25015)

Mon Mar 29 09:08:10 EDT 2021

https://github.com/python/cpython/commit/ed753d94856213ae9fc028195f670e66a24e2334
commit: ed753d94856213ae9fc028195f670e66a24e2334
branch: 3.9
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2021-03-29T06:08:00-07:00
summary:

bpo-42988: Remove the pydoc getfile feature (GH-25015)


CVE-2021-3426: Remove the "getfile" feature of the pydoc module which
could be abused to read arbitrary files on the disk (directory
traversal vulnerability). Moreover, even source code of Python
modules can contain sensitive data like passwords. Vulnerability
reported by David Schwörer.
(cherry picked from commit 9b999479c0022edfc9835a8a1f06e046f3881048)

Co-authored-by: Victor Stinner <vstinner at python.org>

files:
A Misc/NEWS.d/next/Security/2021-03-24-14-16-56.bpo-42988.P2aNco.rst
M Lib/pydoc.py
M Lib/test/test_pydoc.py

diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index 35ef3ebdc688e..ffa4b62c1f17b 100755
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -2457,9 +2457,6 @@ def page(self, title, contents):
 %s</head><body bgcolor="#f0f0f8">%s<div style="clear:both;padding-top:.5em;">%s</div>
 </body></html>''' % (title, css_link, html_navbar(), contents)
 
-        def filelink(self, url, path):
-            return '<a href="getfile?key=%s">%s</a>' % (url, path)
-
 
     html = _HTMLDoc()
 
@@ -2545,19 +2542,6 @@ def bltinlink(name):
             'key = %s' % key, '#ffffff', '#ee77aa', '<br>'.join(results))
         return 'Search Results', contents
 
-    def html_getfile(path):
-        """Get and display a source file listing safely."""
-        path = urllib.parse.unquote(path)
-        with tokenize.open(path) as fp:
-            lines = html.escape(fp.read())
-        body = '<pre>%s</pre>' % lines
-        heading = html.heading(
-            '<big><big><strong>File Listing</strong></big></big>',
-            '#ffffff', '#7799ee')
-        contents = heading + html.bigsection(
-            'File: %s' % path, '#ffffff', '#ee77aa', body)
-        return 'getfile %s' % path, contents
-
     def html_topics():
         """Index of topic texts available."""
 
@@ -2649,8 +2633,6 @@ def get_html_page(url):
                 op, _, url = url.partition('=')
                 if op == "search?key":
                     title, content = html_search(url)
-                elif op == "getfile?key":
-                    title, content = html_getfile(url)
                 elif op == "topic?key":
                     # try topics first, then objects.
                     try:
diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py
index ffabb7f1b9407..0bbdc42c635be 100644
--- a/Lib/test/test_pydoc.py
+++ b/Lib/test/test_pydoc.py
@@ -1374,18 +1374,12 @@ def test_url_requests(self):
             ("topic?key=def", "Pydoc: KEYWORD def"),
             ("topic?key=STRINGS", "Pydoc: TOPIC STRINGS"),
             ("foobar", "Pydoc: Error - foobar"),
-            ("getfile?key=foobar", "Pydoc: Error - getfile?key=foobar"),
             ]
 
         with self.restrict_walk_packages():
             for url, title in requests:
                 self.call_url_handler(url, title)
 
-            path = string.__file__
-            title = "Pydoc: getfile " + path
-            url = "getfile?key=" + path
-            self.call_url_handler(url, title)
-
 
 class TestHelper(unittest.TestCase):
     def test_keywords(self):
diff --git a/Misc/NEWS.d/next/Security/2021-03-24-14-16-56.bpo-42988.P2aNco.rst b/Misc/NEWS.d/next/Security/2021-03-24-14-16-56.bpo-42988.P2aNco.rst
new file mode 100644
index 0000000000000..4b42dd05305a8
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2021-03-24-14-16-56.bpo-42988.P2aNco.rst
@@ -0,0 +1,4 @@
+CVE-2021-3426: Remove the ``getfile`` feature of the :mod:`pydoc` module which
+could be abused to read arbitrary files on the disk (directory traversal
+vulnerability). Moreover, even source code of Python modules can contain
+sensitive data like passwords. Vulnerability reported by David Schwörer.

