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bpo-33661: Clear Authorization header when redirect to cross-site #11292

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bpo-33661: Clear Authorization header when redirect to cross-site #11292

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a4875a2
bpo-33661: Clear Authorization header when redirect to cross-site
kyoshidajp Dec 22, 2018
9068ef0
bpo-33661: Clear Cookie header when redirect to cross-site
kyoshidajp Dec 29, 2018
93ca55e
Merge branch 'main' into bpo-33661
kyoshidajp Jun 30, 2022
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30 changes: 30 additions & 0 deletions Lib/test/test_urllib2.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1326,6 +1326,36 @@ def request(conn, method, url, *pos, **kw):
fp = urllib.request.urlopen("http://python.org/path")
self.assertEqual(fp.geturl(), "http://python.org/path?query")

def test_redirect_to_cross_domain_with_sensitive_header(self):
from_url = "http://example.com/index.html"
to_url = "http://cracker.com/index.html"
h = urllib.request.HTTPRedirectHandler()
o = h.parent = MockOpener()
req = Request(from_url)
req.add_header("Authorization", "Basic foo")
req.add_header("Cookie", "bar")
req.timeout = socket._GLOBAL_DEFAULT_TIMEOUT
h.http_error_302(req, MockFile(), 302, "",
MockHeaders({"location": to_url}))

self.assertNotIn("Authorization", o.req.headers)
self.assertNotIn("Cookie", o.req.headers)

def test_redirect_to_same_domain_with_sensitive_header(self):
from_url = "http://example.com/index.html"
to_url = "http://example.com/index.html"
h = urllib.request.HTTPRedirectHandler()
o = h.parent = MockOpener()
req = Request(from_url)
req.add_header("Authorization", "Basic foo")
req.add_header("Cookie", "bar")
req.timeout = socket._GLOBAL_DEFAULT_TIMEOUT
h.http_error_302(req, MockFile(), 302, "",
MockHeaders({"location": to_url}))

self.assertIn("Authorization", o.req.headers)
self.assertIn("Cookie", o.req.headers)

def test_redirect_encoding(self):
# Some characters in the redirect target may need special handling,
# but most ASCII characters should be treated as already encoded
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9 changes: 8 additions & 1 deletion Lib/urllib/request.py
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Original file line number Diff line number Diff line change
Expand Up @@ -678,11 +678,18 @@ def redirect_request(self, req, fp, code, msg, headers, newurl):
CONTENT_HEADERS = ("content-length", "content-type")
newheaders = {k: v for k, v in req.headers.items()
if k.lower() not in CONTENT_HEADERS}
return Request(newurl,
newrequest = Request(newurl,
headers=newheaders,
origin_req_host=req.origin_req_host,
unverifiable=True)

SENSITIVE_HEADERS = ("authorization", "cookie")
if newrequest.host != req.host:
newrequest.headers = {k: v for k, v in newrequest.headers.items()
if k.lower() not in SENSITIVE_HEADERS}

return newrequest

# Implementation note: To avoid the server sending us into an
# infinite loop, the request object needs to track what URLs we
# have already seen. Do this by adding a handler-specific
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