From c734f873270cf9ca414832423f7aad98443c379f Mon Sep 17 00:00:00 2001

From: Lumir Balhar <lbalhar@redhat.com>

Date: Thu, 9 Jan 2020 11:26:24 +0100

Subject: [PATCH] CVE-2018-20060

---

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

 util/retry.py  | 12 +++++++++++-

 2 files changed, 21 insertions(+), 2 deletions(-)

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

index 4ae9174..bfa5115 100644

--- a/poolmanager.py

+++ b/poolmanager.py

@@ -312,8 +312,9 @@ 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)

@@ -335,6 +336,14 @@ 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 c603cb4..0b83963 100644

--- a/util/retry.py

+++ b/util/retry.py

@@ -126,6 +126,11 @@ 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

@@ -144,6 +149,8 @@ class Retry(object):

     DEFAULT_METHOD_WHITELIST = frozenset([

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

+    DEFAULT_REDIRECT_HEADERS_BLACKLIST = frozenset(['Authorization'])

+

     RETRY_AFTER_STATUS_CODES = frozenset([413, 429, 503])

     #: Maximum backoff time.

@@ -152,7 +159,8 @@ class Retry(object):

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

                  method_whitelist=DEFAULT_METHOD_WHITELIST, status_forcelist=None,

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

-                 history=None, respect_retry_after_header=True):

+                 history=None, respect_retry_after_header=True,

+                 remove_headers_on_redirect=DEFAULT_REDIRECT_HEADERS_BLACKLIST):

         self.total = total

         self.connect = connect

@@ -171,6 +179,7 @@ class Retry(object):

         self.raise_on_status = raise_on_status

         self.history = history or tuple()

         self.respect_retry_after_header = respect_retry_after_header

+        self.remove_headers_on_redirect = remove_headers_on_redirect

     def new(self, **kw):

         params = dict(

@@ -182,6 +191,7 @@ class Retry(object):

             raise_on_redirect=self.raise_on_redirect,

             raise_on_status=self.raise_on_status,

             history=self.history,

+            remove_headers_on_redirect=self.remove_headers_on_redirect,

         )

         params.update(kw)

         return type(self)(**params)

-- 

2.24.1