File CVE-2019-16056-email-parse-addr.patch of Package python3-doc.16830
From 3263dacf50e94352fcb3f97cfbc80cfee5723a56 Mon Sep 17 00:00:00 2001
From: jpic <jpic@yourlabs.org>
Date: Wed, 3 Jul 2019 07:27:12 +0200
Subject: [PATCH] bpo-34155: Fail parse of multiple email domains
Before:
>>> email.message_from_string('From: a@malicious.org@important.com', policy=email.policy.default)['from'].addresses
(Address(display_name='', username='a', domain='malicious.org'),)
>>> parseaddr('a@malicious.org@important.com')
('', 'a@malicious.org')
After:
>>> email.message_from_string('From: a@malicious.org@important.com', policy=email.policy.default)['from'].addresses
(Address(display_name='', username='', domain=''),)
>>> parseaddr('a@malicious.org@important.com')
('', '')
Thanks @maxking for kind patch review and patch contribution.
---
Lib/email/_header_value_parser.py | 2 ++
Lib/email/_parseaddr.py | 11 ++++++++++-
Lib/test/test_email/test__header_value_parser.py | 10 ++++++++++
Lib/test/test_email/test_email.py | 14 ++++++++++++++
.../2019-05-04-13-33-37.bpo-34155.MJll68.rst | 1 +
5 files changed, 37 insertions(+), 1 deletion(-)
create mode 100644 Misc/NEWS.d/next/Security/2019-05-04-13-33-37.bpo-34155.MJll68.rst
--- a/Lib/email/_header_value_parser.py
+++ b/Lib/email/_header_value_parser.py
@@ -1963,6 +1963,8 @@ def get_domain(value):
token, value = get_dot_atom(value)
except errors.HeaderParseError:
token, value = get_atom(value)
+ if value and value[0] == '@':
+ raise errors.HeaderParseError('Invalid Domain')
if leader is not None:
token[:0] = [leader]
domain.append(token)
--- a/Lib/email/_parseaddr.py
+++ b/Lib/email/_parseaddr.py
@@ -379,7 +379,12 @@ class AddrlistClass:
aslist.append('@')
self.pos += 1
self.gotonext()
- return EMPTYSTRING.join(aslist) + self.getdomain()
+ domain = self.getdomain()
+ if not domain:
+ # Invalid domain, return an empty address instead of returning a
+ # local part to denote failed parsing.
+ return EMPTYSTRING
+ return EMPTYSTRING.join(aslist) + domain
def getdomain(self):
"""Get the complete domain name from an address."""
@@ -394,6 +399,10 @@ class AddrlistClass:
elif self.field[self.pos] == '.':
self.pos += 1
sdlist.append('.')
+ elif self.field[self.pos] == '@':
+ # bpo-34155: Don't parse domains with two `@` like
+ # `a@malicious.org@important.com`.
+ return EMPTYSTRING
elif self.field[self.pos] in self.atomends:
break
else:
--- a/Lib/test/test_email/test__header_value_parser.py
+++ b/Lib/test/test_email/test__header_value_parser.py
@@ -1418,6 +1418,16 @@ class TestParser(TestParserMixin, TestEm
self.assertEqual(addr_spec.domain, 'example.com')
self.assertEqual(addr_spec.addr_spec, 'star.a.star@example.com')
+ def test_get_addr_spec_multiple_domains(self):
+ with self.assertRaises(errors.HeaderParseError):
+ parser.get_addr_spec('star@a.star@example.com')
+
+ with self.assertRaises(errors.HeaderParseError):
+ parser.get_addr_spec('star@a@example.com')
+
+ with self.assertRaises(errors.HeaderParseError):
+ parser.get_addr_spec('star@172.17.0.1@example.com')
+
# get_obs_route
def test_get_obs_route_simple(self):
--- a/Lib/test/test_email/test_email.py
+++ b/Lib/test/test_email/test_email.py
@@ -2984,6 +2984,20 @@ class TestMiscellaneous(TestEmailBase):
self.assertEqual(utils.parseaddr('<>'), ('', ''))
self.assertEqual(utils.formataddr(utils.parseaddr('<>')), '')
+ def test_parseaddr_multiple_domains(self):
+ self.assertEqual(
+ utils.parseaddr('a@b@c'),
+ ('', '')
+ )
+ self.assertEqual(
+ utils.parseaddr('a@b.c@c'),
+ ('', '')
+ )
+ self.assertEqual(
+ utils.parseaddr('a@172.17.0.1@c'),
+ ('', '')
+ )
+
def test_noquote_dump(self):
self.assertEqual(
utils.formataddr(('A Silly Person', 'person@dom.ain')),
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2019-05-04-13-33-37.bpo-34155.MJll68.rst
@@ -0,0 +1 @@
+Fix parsing of invalid email addresses with more than one ``@`` (e.g. a@b@c.com.) to not return the part before 2nd ``@`` as valid email address. Patch by maxking & jpic.
