[Python-checkins] cpython (merge 3.5 -> 3.5): merge heads

Sun Jul 31 02:51:50 EDT 2016

https://hg.python.org/cpython/rev/7062eaee3adf
changeset: 102504:7062eaee3adf
branch: 3.5
parent: 102499:095b424127e7
parent: 102503:a0ac52ed8f79
user: Senthil Kumaran <senthil at uthcode.com>
date: Sat Jul 30 23:48:19 2016 -0700
summary:
 merge heads
files:
 Doc/howto/urllib2.rst | 5 +++++
 Doc/library/urllib.request.rst | 15 +++++++++++++++
 Lib/test/test_urllib.py | 12 ++++++++++++
 Lib/urllib/request.py | 6 ++++++
 Misc/NEWS | 4 ++++
 5 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst
--- a/Doc/howto/urllib2.rst
+++ b/Doc/howto/urllib2.rst
@@ -538,6 +538,11 @@
 through a proxy. However, this can be enabled by extending urllib.request as
 shown in the recipe [#]_.
 
+.. note::
+
+ ``HTTP_PROXY`` will be ignored if a variable ``REQUEST_METHOD`` is set; see
+ the documentation on :func:`~urllib.request.getproxies`.
+
 
 Sockets and Layers
 ==================
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -173,6 +173,16 @@
 If both lowercase and uppercase environment variables exist (and disagree),
 lowercase is preferred.
 
+ .. note::
+
+ If the environment variable ``REQUEST_METHOD`` is set, which usually
+ indicates your script is running in a CGI environment, the environment
+ variable ``HTTP_PROXY`` (uppercase ``_PROXY``) will be ignored. This is
+ because that variable can be injected by a client using the "Proxy:" HTTP
+ header. If you need to use an HTTP proxy in a CGI environment, either use
+ ``ProxyHandler`` explicitly, or make sure the variable name is in
+ lowercase (or at least the ``_proxy`` suffix).
+
 
 The following classes are provided:
 
@@ -280,6 +290,11 @@
 list of hostname suffixes, optionally with ``:port`` appended, for example
 ``cern.ch,ncsa.uiuc.edu,some.host:8080``.
 
+ .. note::
+
+ ``HTTP_PROXY`` will be ignored if a variable ``REQUEST_METHOD`` is set;
+ see the documentation on :func:`~urllib.request.getproxies`.
+
 
 .. class:: HTTPPasswordMgr()
 
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -232,6 +232,18 @@
 self.assertTrue(urllib.request.proxy_bypass_environment('anotherdomain.com:8888'))
 self.assertTrue(urllib.request.proxy_bypass_environment('newdomain.com:1234'))
 
+ def test_proxy_cgi_ignore(self):
+ try:
+ self.env.set('HTTP_PROXY', 'http://somewhere:3128')
+ proxies = urllib.request.getproxies_environment()
+ self.assertEqual('http://somewhere:3128', proxies['http'])
+ self.env.set('REQUEST_METHOD', 'GET')
+ proxies = urllib.request.getproxies_environment()
+ self.assertNotIn('http', proxies)
+ finally:
+ self.env.unset('REQUEST_METHOD')
+ self.env.unset('HTTP_PROXY')
+
 def test_proxy_bypass_environment_host_match(self):
 bypass = urllib.request.proxy_bypass_environment
 self.env.set('NO_PROXY',
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -2412,6 +2412,12 @@
 name = name.lower()
 if value and name[-6:] == '_proxy':
 proxies[name[:-6]] = value
+ # CVE-2016-1000110 - If we are running as CGI script, forget HTTP_PROXY
+ # (non-all-lowercase) as it may be set from the web server by a "Proxy:"
+ # header from the client
+ # If "proxy" is lowercase, it will still be used thanks to the next block
+ if 'REQUEST_METHOD' in os.environ:
+ proxies.pop('http', None)
 for name, value in os.environ.items():
 if name[-6:] == '_proxy':
 name = name.lower()
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -34,6 +34,10 @@
 Library
 -------
 
+- Issue #27568: Prevent HTTPoxy attack (CVE-2016-1000110). Ignore the
+ HTTP_PROXY variable when REQUEST_METHOD environment is set, which indicates
+ that the script is in CGI mode.
+
 - Issue #27656: Do not assume sched.h defines any SCHED_* constants.
 
 - Issue #27130: In the "zlib" module, fix handling of large buffers
-- 
Repository URL: https://hg.python.org/cpython
