From 7998d12bc56fcc8dca7bd05fd7f369a4e8e09b62 Mon Sep 17 00:00:00 2001 From: Charalampos Stratakis Date: Mon, 19 Dec 2022 16:33:51 +0100 Subject: [PATCH] CVE-2022-45061: CPU denial of service via inefficient IDNA decoder --- ...service-via-inefficient-idna-decoder.patch | 95 +++++++++++++++++++ python3.6.spec | 15 ++- 2 files changed, 109 insertions(+), 1 deletion(-) create mode 100644 00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch diff --git a/00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch b/00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch new file mode 100644 index 0000000..2eb1aa0 --- /dev/null +++ b/00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch @@ -0,0 +1,95 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: "Miss Islington (bot)" + <31488909+miss-islington@users.noreply.github.com> +Date: Mon, 7 Nov 2022 19:22:14 -0800 +Subject: [PATCH] 00394: CVE-2022-45061: CPU denial of service via inefficient + IDNA decoder + +gh-98433: Fix quadratic time idna decoding. + +There was an unnecessary quadratic loop in idna decoding. This restores +the behavior to linear. + +(cherry picked from commit a6f6c3a3d6f2b580f2d87885c9b8a9350ad7bf15) + +Co-authored-by: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> +Co-authored-by: Gregory P. Smith +--- + Lib/encodings/idna.py | 32 +++++++++---------- + Lib/test/test_codecs.py | 6 ++++ + ...2-11-04-09-29-36.gh-issue-98433.l76c5G.rst | 6 ++++ + 3 files changed, 27 insertions(+), 17 deletions(-) + create mode 100644 Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst + +diff --git a/Lib/encodings/idna.py b/Lib/encodings/idna.py +index ea4058512f..bf98f51336 100644 +--- a/Lib/encodings/idna.py ++++ b/Lib/encodings/idna.py +@@ -39,23 +39,21 @@ def nameprep(label): + + # Check bidi + RandAL = [stringprep.in_table_d1(x) for x in label] +- for c in RandAL: +- if c: +- # There is a RandAL char in the string. Must perform further +- # tests: +- # 1) The characters in section 5.8 MUST be prohibited. +- # This is table C.8, which was already checked +- # 2) If a string contains any RandALCat character, the string +- # MUST NOT contain any LCat character. +- if any(stringprep.in_table_d2(x) for x in label): +- raise UnicodeError("Violation of BIDI requirement 2") +- +- # 3) If a string contains any RandALCat character, a +- # RandALCat character MUST be the first character of the +- # string, and a RandALCat character MUST be the last +- # character of the string. +- if not RandAL[0] or not RandAL[-1]: +- raise UnicodeError("Violation of BIDI requirement 3") ++ if any(RandAL): ++ # There is a RandAL char in the string. Must perform further ++ # tests: ++ # 1) The characters in section 5.8 MUST be prohibited. ++ # This is table C.8, which was already checked ++ # 2) If a string contains any RandALCat character, the string ++ # MUST NOT contain any LCat character. ++ if any(stringprep.in_table_d2(x) for x in label): ++ raise UnicodeError("Violation of BIDI requirement 2") ++ # 3) If a string contains any RandALCat character, a ++ # RandALCat character MUST be the first character of the ++ # string, and a RandALCat character MUST be the last ++ # character of the string. ++ if not RandAL[0] or not RandAL[-1]: ++ raise UnicodeError("Violation of BIDI requirement 3") + + return label + +diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py +index 56485de3f6..a798d1f287 100644 +--- a/Lib/test/test_codecs.py ++++ b/Lib/test/test_codecs.py +@@ -1640,6 +1640,12 @@ class IDNACodecTest(unittest.TestCase): + self.assertEqual("pyth\xf6n.org".encode("idna"), b"xn--pythn-mua.org") + self.assertEqual("pyth\xf6n.org.".encode("idna"), b"xn--pythn-mua.org.") + ++ def test_builtin_decode_length_limit(self): ++ with self.assertRaisesRegex(UnicodeError, "too long"): ++ (b"xn--016c"+b"a"*1100).decode("idna") ++ with self.assertRaisesRegex(UnicodeError, "too long"): ++ (b"xn--016c"+b"a"*70).decode("idna") ++ + def test_stream(self): + r = codecs.getreader("idna")(io.BytesIO(b"abc")) + r.read(3) +diff --git a/Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst b/Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst +new file mode 100644 +index 0000000000..5185fac2e2 +--- /dev/null ++++ b/Misc/NEWS.d/next/Security/2022-11-04-09-29-36.gh-issue-98433.l76c5G.rst +@@ -0,0 +1,6 @@ ++The IDNA codec decoder used on DNS hostnames by :mod:`socket` or :mod:`asyncio` ++related name resolution functions no longer involves a quadratic algorithm. ++This prevents a potential CPU denial of service if an out-of-spec excessive ++length hostname involving bidirectional characters were decoded. Some protocols ++such as :mod:`urllib` http ``3xx`` redirects potentially allow for an attacker ++to supply such a name. diff --git a/python3.6.spec b/python3.6.spec index c420acd..807946a 100644 --- a/python3.6.spec +++ b/python3.6.spec @@ -17,7 +17,7 @@ URL: https://www.python.org/ #global prerel ... %global upstream_version %{general_version}%{?prerel} Version: %{general_version}%{?prerel:~%{prerel}} -Release: 14%{?dist} +Release: 15%{?dist} License: Python @@ -569,6 +569,15 @@ Patch387: 00387-cve-2020-10735-prevent-dos-by-very-large-int.patch # [2]: https://mouha.be/sha-3-buffer-overflow/ Patch392: 00392-cve-2022-37454-fix-buffer-overflows-in-_sha3-module.patch +# 00394 # 377cbc015f738fdea510969d0dbe266748b6bb09 +# CVE-2022-45061: CPU denial of service via inefficient IDNA decoder +# +# gh-98433: Fix quadratic time idna decoding. +# +# There was an unnecessary quadratic loop in idna decoding. This restores +# the behavior to linear. +Patch394: 00394-cve-2022-45061-cpu-denial-of-service-via-inefficient-idna-decoder.patch + # (New patches go here ^^^) # # When adding new patches to "python" and "python3" in Fedora, EL, etc., @@ -1759,6 +1768,10 @@ CheckPython optimized # ====================================================== %changelog +* Mon Dec 19 2022 Charalampos Stratakis - 3.6.15-15 +- Security fix for CVE-2022-45061: CPU denial of service via inefficient IDNA decoder + Related: rhbz#2144072 + * Thu Nov 10 2022 Miro Hrončok - 3.6.15-14 - CVE-2022-37454: Fix buffer overflows in _sha3 module Related: rhbz#2140200