From 97ee1f80870745bf6c542ee2f184c9e468672714 Mon Sep 17 00:00:00 2001 From: Sinan Kaya Date: Fri, 5 Oct 2018 00:39:08 +0000 Subject: python3: CVE-2018-1061 * CVE-2018-1060 Prevent low-grade poplib REDOS: The regex to test a mail server's timestamp is susceptible to catastrophic backtracking on long evil responses from the server. Happily, the maximum length of malicious inputs is 2K thanks to a limit introduced in the fix for CVE-2013-1752. * CVE-2018-1061 Prevent difflib REDOS The default regex for IS_LINE_JUNK is susceptible to catastrophic backtracking. This is a potential DOS vector. Replace it with an equivalent non-vulnerable regex. Affects < 3.5.6rc1 CVE: CVE-2018-1060 CVE: CVE-2018-1061 Ref: https://access.redhat.com/security/cve/cve-2018-1060 Ref: https://access.redhat.com/security/cve/cve-2018-1061 (From OE-Core rev: 1461bcc72e6649920ecf4226e006e5667c48a21c) Signed-off-by: Sinan Kaya Signed-off-by: Armin Kuster Signed-off-by: Richard Purdie --- .../python/python3/CVE-2018-1061.patch | 165 +++++++++++++++++++++ meta/recipes-devtools/python/python3_3.5.5.bb | 1 + 2 files changed, 166 insertions(+) create mode 100644 meta/recipes-devtools/python/python3/CVE-2018-1061.patch (limited to 'meta/recipes-devtools') diff --git a/meta/recipes-devtools/python/python3/CVE-2018-1061.patch b/meta/recipes-devtools/python/python3/CVE-2018-1061.patch new file mode 100644 index 0000000000..6373be389a --- /dev/null +++ b/meta/recipes-devtools/python/python3/CVE-2018-1061.patch @@ -0,0 +1,165 @@ +From 6d7ef39198856395edd62ef143bfcfaaf2ed6e25 Mon Sep 17 00:00:00 2001 +From: Ned Deily +Date: Sun, 11 Mar 2018 14:29:05 -0400 +Subject: [PATCH] [3.5] bpo-32981: Fix catastrophic backtracking vulns + (GH-5955) (#6034) + +* Prevent low-grade poplib REDOS (CVE-2018-1060) + +The regex to test a mail server's timestamp is susceptible to +catastrophic backtracking on long evil responses from the server. + +Happily, the maximum length of malicious inputs is 2K thanks +to a limit introduced in the fix for CVE-2013-1752. + +A 2KB evil response from the mail server would result in small slowdowns +(milliseconds vs. microseconds) accumulated over many apop calls. +This is a potential DOS vector via accumulated slowdowns. + +Replace it with a similar non-vulnerable regex. + +The new regex is RFC compliant. +The old regex was non-compliant in edge cases. + +* Prevent difflib REDOS (CVE-2018-1061) + +The default regex for IS_LINE_JUNK is susceptible to +catastrophic backtracking. +This is a potential DOS vector. + +Replace it with an equivalent non-vulnerable regex. + +Also introduce unit and REDOS tests for difflib. + +Co-authored-by: Tim Peters +Co-authored-by: Christian Heimes . +(cherry picked from commit 0e6c8ee2358a2e23117501826c008842acb835ac) +CVE: CVE-2018-1061 +CVE: CVE-2018-1060 +Upstream-Status: Backport [https://github.com/python/cpython/commit/937ac1fe069a4dc8471dff205f553d82e724015b] +Signed-off-by: Sinan Kaya +--- + Lib/difflib.py | 2 +- + Lib/poplib.py | 2 +- + Lib/test/test_difflib.py | 22 ++++++++++++++++++- + Lib/test/test_poplib.py | 12 +++++++++- + Misc/ACKS | 1 + + .../2018-03-02-10-24-52.bpo-32981.O_qDyj.rst | 4 ++++ + 6 files changed, 39 insertions(+), 4 deletions(-) + create mode 100644 Misc/NEWS.d/next/Security/2018-03-02-10-24-52.bpo-32981.O_qDyj.rst + +diff --git a/Lib/difflib.py b/Lib/difflib.py +index 076bbac01d..b4ec335056 100644 +--- a/Lib/difflib.py ++++ b/Lib/difflib.py +@@ -1083,7 +1083,7 @@ class Differ: + + import re + +-def IS_LINE_JUNK(line, pat=re.compile(r"\s*#?\s*$").match): ++def IS_LINE_JUNK(line, pat=re.compile(r"\s*(?:#\s*)?$").match): + r""" + Return 1 for ignorable line: iff `line` is blank or contains a single '#'. + +diff --git a/Lib/poplib.py b/Lib/poplib.py +index 516b6f060d..2437ea0e27 100644 +--- a/Lib/poplib.py ++++ b/Lib/poplib.py +@@ -308,7 +308,7 @@ class POP3: + return self._shortcmd('RPOP %s' % user) + + +- timestamp = re.compile(br'\+OK.*(<[^>]+>)') ++ timestamp = re.compile(br'\+OK.[^<]*(<.*>)') + + def apop(self, user, password): + """Authorisation +diff --git a/Lib/test/test_difflib.py b/Lib/test/test_difflib.py +index ab9debf8e2..b6c8a7dd5b 100644 +--- a/Lib/test/test_difflib.py ++++ b/Lib/test/test_difflib.py +@@ -466,13 +466,33 @@ class TestBytes(unittest.TestCase): + list(generator(*args)) + self.assertEqual(msg, str(ctx.exception)) + ++class TestJunkAPIs(unittest.TestCase): ++ def test_is_line_junk_true(self): ++ for line in ['#', ' ', ' #', '# ', ' # ', '']: ++ self.assertTrue(difflib.IS_LINE_JUNK(line), repr(line)) ++ ++ def test_is_line_junk_false(self): ++ for line in ['##', ' ##', '## ', 'abc ', 'abc #', 'Mr. Moose is up!']: ++ self.assertFalse(difflib.IS_LINE_JUNK(line), repr(line)) ++ ++ def test_is_line_junk_REDOS(self): ++ evil_input = ('\t' * 1000000) + '##' ++ self.assertFalse(difflib.IS_LINE_JUNK(evil_input)) ++ ++ def test_is_character_junk_true(self): ++ for char in [' ', '\t']: ++ self.assertTrue(difflib.IS_CHARACTER_JUNK(char), repr(char)) ++ ++ def test_is_character_junk_false(self): ++ for char in ['a', '#', '\n', '\f', '\r', '\v']: ++ self.assertFalse(difflib.IS_CHARACTER_JUNK(char), repr(char)) + + def test_main(): + difflib.HtmlDiff._default_prefix = 0 + Doctests = doctest.DocTestSuite(difflib) + run_unittest( + TestWithAscii, TestAutojunk, TestSFpatches, TestSFbugs, +- TestOutputFormat, TestBytes, Doctests) ++ TestOutputFormat, TestBytes, TestJunkAPIs, Doctests) + + if __name__ == '__main__': + test_main() +diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py +index bceeb93ad1..799e403652 100644 +--- a/Lib/test/test_poplib.py ++++ b/Lib/test/test_poplib.py +@@ -300,9 +300,19 @@ class TestPOP3Class(TestCase): + def test_rpop(self): + self.assertOK(self.client.rpop('foo')) + +- def test_apop(self): ++ def test_apop_normal(self): + self.assertOK(self.client.apop('foo', 'dummypassword')) + ++ def test_apop_REDOS(self): ++ # Replace welcome with very long evil welcome. ++ # NB The upper bound on welcome length is currently 2048. ++ # At this length, evil input makes each apop call take ++ # on the order of milliseconds instead of microseconds. ++ evil_welcome = b'+OK' + (b'<' * 1000000) ++ with test_support.swap_attr(self.client, 'welcome', evil_welcome): ++ # The evil welcome is invalid, so apop should throw. ++ self.assertRaises(poplib.error_proto, self.client.apop, 'a', 'kb') ++ + def test_top(self): + expected = (b'+OK 116 bytes', + [b'From: postmaster@python.org', b'Content-Type: text/plain', +diff --git a/Misc/ACKS b/Misc/ACKS +index 1a35aad66c..72c5d740bd 100644 +--- a/Misc/ACKS ++++ b/Misc/ACKS +@@ -341,6 +341,7 @@ Kushal Das + Jonathan Dasteel + Pierre-Yves David + A. Jesse Jiryu Davis ++Jamie (James C.) Davis + Merlijn van Deen + John DeGood + Ned Deily +diff --git a/Misc/NEWS.d/next/Security/2018-03-02-10-24-52.bpo-32981.O_qDyj.rst b/Misc/NEWS.d/next/Security/2018-03-02-10-24-52.bpo-32981.O_qDyj.rst +new file mode 100644 +index 0000000000..9ebabb44f9 +--- /dev/null ++++ b/Misc/NEWS.d/next/Security/2018-03-02-10-24-52.bpo-32981.O_qDyj.rst +@@ -0,0 +1,4 @@ ++Regexes in difflib and poplib were vulnerable to catastrophic backtracking. ++These regexes formed potential DOS vectors (REDOS). They have been ++refactored. This resolves CVE-2018-1060 and CVE-2018-1061. ++Patch by Jamie Davis. +-- +2.19.0 + diff --git a/meta/recipes-devtools/python/python3_3.5.5.bb b/meta/recipes-devtools/python/python3_3.5.5.bb index 4dae4fa4c6..c28be32925 100644 --- a/meta/recipes-devtools/python/python3_3.5.5.bb +++ b/meta/recipes-devtools/python/python3_3.5.5.bb @@ -37,6 +37,7 @@ SRC_URI += "\ file://configure.ac-fix-LIBPL.patch \ file://0001-Issue-21272-Use-_sysconfigdata.py-to-initialize-dist.patch \ file://pass-missing-libraries-to-Extension-for-mul.patch \ + file://CVE-2018-1061.patch \ " SRC_URI[md5sum] = "f3763edf9824d5d3a15f5f646083b6e0" SRC_URI[sha256sum] = "063d2c3b0402d6191b90731e0f735c64830e7522348aeb7ed382a83165d45009" -- cgit v1.2.3-54-g00ecf