[1.3.X] Fixed a security issue in get_host.

Full disclosure and new release forthcoming.

Author: apollo13

django/http/__init__.py

@@ -129,6 +129,8 @@ def __init__(self, *args, **kwargs):
 RESERVED_CHARS="!*'();:@&=+$,/?%#[]"
 
 absolute_http_url_re = re.compile(r"^https?://", re.I)
+host_validation_re = re.compile(r"^([a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9:]+\])(:\d+)?$")
+
 
 class Http404(Exception):
  pass
@@ -167,7 +169,7 @@ def get_host(self):
  host = '%s:%s' % (host, server_port)
 
  # Disallow potentially poisoned hostnames.
- if set(';/?@&=+$,').intersection(host):
+ if not host_validation_re.match(host.lower()):
  raise SuspiciousOperation('Invalid HTTP_HOST header: %s' % host)
 
  return host

tests/regressiontests/requests/tests.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 import time
 from datetime import datetime, timedelta
 from StringIO import StringIO
@@ -110,13 +111,15 @@ def test_http_get_host(self):
  '12.34.56.78:443',
  '[2001:19f0:feee::dead:beef:cafe]',
  '[2001:19f0:feee::dead:beef:cafe]:8080',
+ 'xn--4ca9at.com', # Punnycode for öäü.com
  ]
 
  poisoned_hosts = [
  'example.com@evil.tld',
  'example.com:dr.frankenstein@evil.tld',
- 'example.com:someone@somestie.com:80',
- 'example.com:80/badpath'
+ 'example.com:dr.frankenstein@evil.tld:80',
+ 'example.com:80/badpath',
+ 'example.com: recovermypassword.com',
  ]
 
  for host in legit_hosts:
@@ -187,13 +190,15 @@ def test_http_get_host_with_x_forwarded_host(self):
  '12.34.56.78:443',
  '[2001:19f0:feee::dead:beef:cafe]',
  '[2001:19f0:feee::dead:beef:cafe]:8080',
+ 'xn--4ca9at.com', # Punnycode for öäü.com
  ]
 
  poisoned_hosts = [
  'example.com@evil.tld',
  'example.com:dr.frankenstein@evil.tld',
  'example.com:dr.frankenstein@evil.tld:80',
- 'example.com:80/badpath'
+ 'example.com:80/badpath',
+ 'example.com: recovermypassword.com',
  ]
 
  for host in legit_hosts: