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authorMiss Islington (bot) <31488909+miss-islington@users.noreply.github.com>2019-06-05 03:23:37 -0700
committerGitHub <noreply@github.com>2019-06-05 03:23:37 -0700
commitf62a372928fbf6a2ba722f12f069b75ca6ad16fb (patch)
treedff68e8171f97adb917dd6df5062ee167cfb6b4d /Lib
parent3d75bd15ac82575967db367c517d7e6e703a6de3 (diff)
downloadcpython-git-f62a372928fbf6a2ba722f12f069b75ca6ad16fb.tar.gz
bpo-30835: email: Fix AttributeError when parsing invalid CTE (GH-13598)
* bpo-30835: email: Fix AttributeError when parsing invalid Content-Transfer-Encoding Parsing an email containing a multipart Content-Type, along with a Content-Transfer-Encoding containing an invalid (non-ASCII-decodable) byte will fail. email.feedparser.FeedParser._parsegen() gets the header and attempts to convert it to lowercase before comparing it with the accepted encodings, but as the header contains an invalid byte, it's returned as a Header object rather than a str. Cast the Content-Transfer-Encoding header to a str to avoid this. Found using the AFL fuzzer. Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Andrew Donnellan <andrew@donnellan.id.au> * Add email and NEWS entry for the bugfix. (cherry picked from commit aa79707262f893428665ef45b5e879129abca4aa) Co-authored-by: Abhilash Raj <maxking@users.noreply.github.com>
Diffstat (limited to 'Lib')
-rw-r--r--Lib/email/feedparser.py2
-rw-r--r--Lib/test/test_email/test_email.py9
2 files changed, 10 insertions, 1 deletions
diff --git a/Lib/email/feedparser.py b/Lib/email/feedparser.py
index 7c07ca8645..97d3f5144d 100644
--- a/Lib/email/feedparser.py
+++ b/Lib/email/feedparser.py
@@ -320,7 +320,7 @@ class FeedParser:
self._cur.set_payload(EMPTYSTRING.join(lines))
return
# Make sure a valid content type was specified per RFC 2045:6.4.
- if (self._cur.get('content-transfer-encoding', '8bit').lower()
+ if (str(self._cur.get('content-transfer-encoding', '8bit')).lower()
not in ('7bit', '8bit', 'binary')):
defect = errors.InvalidMultipartContentTransferEncodingDefect()
self.policy.handle_defect(self._cur, defect)
diff --git a/Lib/test/test_email/test_email.py b/Lib/test/test_email/test_email.py
index dfb3be8438..c29cc56203 100644
--- a/Lib/test/test_email/test_email.py
+++ b/Lib/test/test_email/test_email.py
@@ -1466,6 +1466,15 @@ Blah blah blah
g.flatten(msg)
self.assertEqual(b.getvalue(), source + b'>From R\xc3\xb6lli\n')
+ def test_mutltipart_with_bad_bytes_in_cte(self):
+ # bpo30835
+ source = textwrap.dedent("""\
+ From: aperson@example.com
+ Content-Type: multipart/mixed; boundary="1"
+ Content-Transfer-Encoding: \xc8
+ """).encode('utf-8')
+ msg = email.message_from_bytes(source)
+
# Test the basic MIMEAudio class
class TestMIMEAudio(unittest.TestCase):