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.
This commit is contained in:
Victor Stinner 2021-03-29 14:40:40 +02:00 committed by GitHub
parent 4827483f47
commit 9b999479c0
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 4 additions and 24 deletions

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@ -2456,9 +2456,6 @@ def _url_handler(url, content_type="text/html"):
%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()
@ -2544,19 +2541,6 @@ def _url_handler(url, content_type="text/html"):
'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."""
@ -2648,8 +2632,6 @@ def _url_handler(url, content_type="text/html"):
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:

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@ -1374,18 +1374,12 @@ class PydocUrlHandlerTest(PydocBaseTest):
("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):

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@ -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.