Skip to content

bpo-37461: Fix infinite loop in parsing of specially crafted email headers #14794

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Jul 17, 2019
Merged

bpo-37461: Fix infinite loop in parsing of specially crafted email headers #14794

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
b906a85
bpo-37461: Fix infinite loop in parsing of specially crafted email he…
maxking Jul 16, 2019
23a1fbc
Add test and NEWS entry.
maxking Jul 16, 2019
cc4ed70
Fix the test to invoke the right infinite loop.
maxking Jul 17, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions Lib/email/_header_value_parser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2496,6 +2496,9 @@ def get_parameter(value):
while value:
if value[0] in WSP:
token, value = get_fws(value)
elif value[0] == '"':
token = ValueTerminal('"', 'DQUOTE')
value = value[1:]
else:
token, value = get_qcontent(value)
v.append(token)
Expand Down
7 changes: 7 additions & 0 deletions Lib/test/test_email/test__header_value_parser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2710,6 +2710,13 @@ def mime_parameters_as_value(self,
# Defects are apparent missing *0*, and two 'out of sequence'.
[errors.InvalidHeaderDefect]*3),

# bpo-37461: Check that we don't go into an infinite loop.
'extra_dquote': (
'r*="\'a\'\\"',
' r="\\""',
'r*=\'a\'"',
[('r', '"')],
[errors.InvalidHeaderDefect]*2),
}

@parameterize
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Security/2019-07-16-08-11-00.bpo-37461.1Ahz7O.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Fix an inifite loop when parsing specially crafted email headers. Patch by
Abhilash Raj.