From 20f7d039446f71c40ea240c0a9f6e2465659ec68 Mon Sep 17 00:00:00 2001

From: Lumir Balhar <lbalhar@redhat.com>

Date: Mon, 13 Jan 2020 09:31:42 +0100

Subject: [PATCH 1/2] CVE-2018-20060

---

 poolmanager.py | 11 ++++++++++-

 util/retry.py  | 11 ++++++++++-

 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/poolmanager.py b/poolmanager.py

index 1023dcb..b87f315 100644

--- a/poolmanager.py

+++ b/poolmanager.py

@@ -156,8 +156,9 @@ class PoolManager(RequestMethods):

         kw['assert_same_host'] = False

         kw['redirect'] = False

+

         if 'headers' not in kw:

-            kw['headers'] = self.headers

+            kw['headers'] = self.headers.copy()

         if self.proxy is not None and u.scheme == "http":

             response = conn.urlopen(method, url, **kw)

@@ -179,6 +180,14 @@ class PoolManager(RequestMethods):

         if not isinstance(retries, Retry):

             retries = Retry.from_int(retries, redirect=redirect)

+        # Strip headers marked as unsafe to forward to the redirected location.

+        # Check remove_headers_on_redirect to avoid a potential network call within

+        # conn.is_same_host() which may use socket.gethostbyname() in the future.

+        if (retries.remove_headers_on_redirect

+                and not conn.is_same_host(redirect_location)):

+            for header in retries.remove_headers_on_redirect:

+                kw['headers'].pop(header, None)

+

         try:

             retries = retries.increment(method, url, response=response, _pool=conn)

         except MaxRetryError:

diff --git a/util/retry.py b/util/retry.py

index 2d3aa20..d6bd74e 100644

--- a/util/retry.py

+++ b/util/retry.py

@@ -103,6 +103,11 @@ class Retry(object):

         exhausted, to raise a MaxRetryError, or to return a response with a

         response code in the 3xx range.

+    :param iterable remove_headers_on_redirect:

+        Sequence of headers to remove from the request when a response

+        indicating a redirect is returned before firing off the redirected

+        request

+

     :param bool raise_on_status: Similar meaning to ``raise_on_redirect``:

         whether we should raise an exception, or return a response,

         if status falls in ``status_forcelist`` range and retries have

@@ -112,13 +117,15 @@ class Retry(object):

     DEFAULT_METHOD_WHITELIST = frozenset([

         'HEAD', 'GET', 'PUT', 'DELETE', 'OPTIONS', 'TRACE'])

+    DEFAULT_REDIRECT_HEADERS_BLACKLIST = frozenset(['Authorization'])

+

     #: Maximum backoff time.

     BACKOFF_MAX = 120

     def __init__(self, total=10, connect=None, read=None, redirect=None,

                  method_whitelist=DEFAULT_METHOD_WHITELIST, status_forcelist=None,

                  backoff_factor=0, raise_on_redirect=True, raise_on_status=True,

-                 _observed_errors=0):

+                 _observed_errors=0, remove_headers_on_redirect=DEFAULT_REDIRECT_HEADERS_BLACKLIST):

         self.total = total

         self.connect = connect

@@ -135,6 +142,7 @@ class Retry(object):

         self.raise_on_redirect = raise_on_redirect

         self.raise_on_status = raise_on_status

         self._observed_errors = _observed_errors  # TODO: use .history instead?

+        self.remove_headers_on_redirect = remove_headers_on_redirect

     def new(self, **kw):

         params = dict(

@@ -146,6 +154,7 @@ class Retry(object):

             raise_on_redirect=self.raise_on_redirect,

             raise_on_status=self.raise_on_status,

             _observed_errors=self._observed_errors,

+            remove_headers_on_redirect=self.remove_headers_on_redirect,

         )

         params.update(kw)

         return type(self)(**params)

-- 

2.24.1