aboutsummaryrefslogtreecommitdiffstats
path: root/meta/recipes-devtools/python/python3/CVE-2019-9636.patch
blob: 72128f0b0d1bcdd4ca2bb605ecad2591448d070c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
From daad2c482c91de32d8305abbccc76a5de8b3a8be Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@microsoft.com>
Date: Thu, 7 Mar 2019 09:08:18 -0800
Subject: [PATCH] bpo-36216: Add check for characters in netloc that normalize
 to separators (GH-12201)

Upstream-Status: Backport
CVE: CVE-2019-9636
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>

---
 Doc/library/urllib.parse.rst                  | 18 +++++++++++++++
 Lib/test/test_urlparse.py                     | 23 +++++++++++++++++++
 Lib/urllib/parse.py                           | 17 ++++++++++++++
 .../2019-03-06-09-38-40.bpo-36216.6q1m4a.rst  |  3 +++
 4 files changed, 61 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst

diff --git a/Doc/library/urllib.parse.rst b/Doc/library/urllib.parse.rst
index 0c8f0f607314..b565e1edd321 100644
--- a/Doc/library/urllib.parse.rst
+++ b/Doc/library/urllib.parse.rst
@@ -124,6 +124,11 @@ or on combining URL components into a URL string.
    Unmatched square brackets in the :attr:`netloc` attribute will raise a
    :exc:`ValueError`.
 
+   Characters in the :attr:`netloc` attribute that decompose under NFKC
+   normalization (as used by the IDNA encoding) into any of ``/``, ``?``,
+   ``#``, ``@``, or ``:`` will raise a :exc:`ValueError`. If the URL is
+   decomposed before parsing, no error will be raised.
+
    .. versionchanged:: 3.2
       Added IPv6 URL parsing capabilities.
 
@@ -136,6 +141,10 @@ or on combining URL components into a URL string.
       Out-of-range port numbers now raise :exc:`ValueError`, instead of
       returning :const:`None`.
 
+   .. versionchanged:: 3.7.3
+      Characters that affect netloc parsing under NFKC normalization will
+      now raise :exc:`ValueError`.
+
 
 .. function:: parse_qs(qs, keep_blank_values=False, strict_parsing=False, encoding='utf-8', errors='replace', max_num_fields=None)
 
@@ -257,10 +266,19 @@ or on combining URL components into a URL string.
    Unmatched square brackets in the :attr:`netloc` attribute will raise a
    :exc:`ValueError`.
 
+   Characters in the :attr:`netloc` attribute that decompose under NFKC
+   normalization (as used by the IDNA encoding) into any of ``/``, ``?``,
+   ``#``, ``@``, or ``:`` will raise a :exc:`ValueError`. If the URL is
+   decomposed before parsing, no error will be raised.
+
    .. versionchanged:: 3.6
       Out-of-range port numbers now raise :exc:`ValueError`, instead of
       returning :const:`None`.
 
+   .. versionchanged:: 3.7.3
+      Characters that affect netloc parsing under NFKC normalization will
+      now raise :exc:`ValueError`.
+
 
 .. function:: urlunsplit(parts)
 
diff --git a/Lib/test/test_urlparse.py b/Lib/test/test_urlparse.py
index be50b47603aa..e6638aee2244 100644
--- a/Lib/test/test_urlparse.py
+++ b/Lib/test/test_urlparse.py
@@ -1,3 +1,5 @@
+import sys
+import unicodedata
 import unittest
 import urllib.parse
 
@@ -984,6 +986,27 @@ def test_all(self):
                 expected.append(name)
         self.assertCountEqual(urllib.parse.__all__, expected)
 
+    def test_urlsplit_normalization(self):
+        # Certain characters should never occur in the netloc,
+        # including under normalization.
+        # Ensure that ALL of them are detected and cause an error
+        illegal_chars = '/:#?@'
+        hex_chars = {'{:04X}'.format(ord(c)) for c in illegal_chars}
+        denorm_chars = [
+            c for c in map(chr, range(128, sys.maxunicode))
+            if (hex_chars & set(unicodedata.decomposition(c).split()))
+            and c not in illegal_chars
+        ]
+        # Sanity check that we found at least one such character
+        self.assertIn('\u2100', denorm_chars)
+        self.assertIn('\uFF03', denorm_chars)
+
+        for scheme in ["http", "https", "ftp"]:
+            for c in denorm_chars:
+                url = "{}://netloc{}false.netloc/path".format(scheme, c)
+                with self.subTest(url=url, char='{:04X}'.format(ord(c))):
+                    with self.assertRaises(ValueError):
+                        urllib.parse.urlsplit(url)
 
 class Utility_Tests(unittest.TestCase):
     """Testcase to test the various utility functions in the urllib."""
diff --git a/Lib/urllib/parse.py b/Lib/urllib/parse.py
index f691ab74f87f..39c5d6a80824 100644
--- a/Lib/urllib/parse.py
+++ b/Lib/urllib/parse.py
@@ -391,6 +391,21 @@ def _splitnetloc(url, start=0):
             delim = min(delim, wdelim)     # use earliest delim position
     return url[start:delim], url[delim:]   # return (domain, rest)
 
+def _checknetloc(netloc):
+    if not netloc or netloc.isascii():
+        return
+    # looking for characters like \u2100 that expand to 'a/c'
+    # IDNA uses NFKC equivalence, so normalize for this check
+    import unicodedata
+    netloc2 = unicodedata.normalize('NFKC', netloc)
+    if netloc == netloc2:
+        return
+    _, _, netloc = netloc.rpartition('@') # anything to the left of '@' is okay
+    for c in '/?#@:':
+        if c in netloc2:
+            raise ValueError("netloc '" + netloc2 + "' contains invalid " +
+                             "characters under NFKC normalization")
+
 def urlsplit(url, scheme='', allow_fragments=True):
     """Parse a URL into 5 components:
     <scheme>://<netloc>/<path>?<query>#<fragment>
@@ -419,6 +434,7 @@ def urlsplit(url, scheme='', allow_fragments=True):
                 url, fragment = url.split('#', 1)
             if '?' in url:
                 url, query = url.split('?', 1)
+            _checknetloc(netloc)
             v = SplitResult('http', netloc, url, query, fragment)
             _parse_cache[key] = v
             return _coerce_result(v)
@@ -442,6 +458,7 @@ def urlsplit(url, scheme='', allow_fragments=True):
         url, fragment = url.split('#', 1)
     if '?' in url:
         url, query = url.split('?', 1)
+    _checknetloc(netloc)
     v = SplitResult(scheme, netloc, url, query, fragment)
     _parse_cache[key] = v
     return _coerce_result(v)
diff --git a/Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst b/Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst
new file mode 100644
index 000000000000..5546394157f9
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2019-03-06-09-38-40.bpo-36216.6q1m4a.rst
@@ -0,0 +1,3 @@
+Changes urlsplit() to raise ValueError when the URL contains characters that
+decompose under IDNA encoding (NFKC-normalization) into characters that
+affect how the URL is parsed.