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[3.7] bpo-34155: Dont parse domains containing @ (GH-13079) #14825

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Merged
merged 1 commit into from
Aug 9, 2019
Merged

[3.7] bpo-34155: Dont parse domains containing @ (GH-13079) #14825

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2 changes: 2 additions & 0 deletions Lib/email/_header_value_parser.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1585,6 +1585,8 @@ 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)
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11 changes: 10 additions & 1 deletion Lib/email/_parseaddr.py
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Original file line number Diff line number Diff line change
Expand Up @@ -379,7 +379,12 @@ def getaddrspec(self):
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."""
Expand All @@ -394,6 +399,10 @@ def getdomain(self):
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:
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10 changes: 10 additions & 0 deletions Lib/test/test_email/test__header_value_parser.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1448,6 +1448,16 @@ def test_get_addr_spec_dot_atom(self):
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):
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14 changes: 14 additions & 0 deletions Lib/test/test_email/test_email.py
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Original file line number Diff line number Diff line change
Expand Up @@ -3041,6 +3041,20 @@ def test_parseaddr_empty(self):
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')),
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1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Security/2019-05-04-13-33-37.bpo-34155.MJll68.rst
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Original file line number Diff line number Diff line change
@@ -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.