package/python: add upstream security fix for CVE-2019-5010
authorPeter Korsgaard <peter@korsgaard.com>
Fri, 1 Feb 2019 12:36:23 +0000 (13:36 +0100)
committerPeter Korsgaard <peter@korsgaard.com>
Sat, 2 Feb 2019 13:27:22 +0000 (14:27 +0100)
Fixes CVE-2019-5010: NULL pointer dereference using a specially crafted X509
certificate

https://bugs.python.org/issue35746

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
package/python/0035-bpo-35746-Fix-segfault-in-ssl-s-cert-parser-GH-11569.patch [new file with mode: 0644]

diff --git a/package/python/0035-bpo-35746-Fix-segfault-in-ssl-s-cert-parser-GH-11569.patch b/package/python/0035-bpo-35746-Fix-segfault-in-ssl-s-cert-parser-GH-11569.patch
new file mode 100644 (file)
index 0000000..9eec6db
--- /dev/null
@@ -0,0 +1,121 @@
+From 06b15424b0dcacb1c551b2a36e739fffa8d0c595 Mon Sep 17 00:00:00 2001
+From: "Miss Islington (bot)"
+ <31488909+miss-islington@users.noreply.github.com>
+Date: Tue, 15 Jan 2019 15:11:52 -0800
+Subject: [PATCH] bpo-35746: Fix segfault in ssl's cert parser (GH-11569)
+
+Fix a NULL pointer deref in ssl module. The cert parser did not handle CRL
+distribution points with empty DP or URI correctly. A malicious or buggy
+certificate can result into segfault.
+
+Signed-off-by: Christian Heimes <christian@python.org>
+
+https://bugs.python.org/issue35746
+(cherry picked from commit a37f52436f9aa4b9292878b72f3ff1480e2606c3)
+
+Co-authored-by: Christian Heimes <christian@python.org>
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ Lib/test/talos-2019-0758.pem                       | 22 ++++++++++++++++++++++
+ Lib/test/test_ssl.py                               | 22 ++++++++++++++++++++++
+ .../2019-01-15-18-16-05.bpo-35746.nMSd0j.rst       |  3 +++
+ Modules/_ssl.c                                     |  4 ++++
+ 4 files changed, 51 insertions(+)
+ create mode 100644 Lib/test/talos-2019-0758.pem
+ create mode 100644 Misc/NEWS.d/next/Security/2019-01-15-18-16-05.bpo-35746.nMSd0j.rst
+
+diff --git a/Lib/test/talos-2019-0758.pem b/Lib/test/talos-2019-0758.pem
+new file mode 100644
+index 0000000000..13b95a77fd
+--- /dev/null
++++ b/Lib/test/talos-2019-0758.pem
+@@ -0,0 +1,22 @@
++-----BEGIN CERTIFICATE-----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++-----END CERTIFICATE-----
+diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
+index e476031702..9240184d98 100644
+--- a/Lib/test/test_ssl.py
++++ b/Lib/test/test_ssl.py
+@@ -72,6 +72,7 @@ NONEXISTINGCERT = data_file("XXXnonexisting.pem")
+ BADKEY = data_file("badkey.pem")
+ NOKIACERT = data_file("nokia.pem")
+ NULLBYTECERT = data_file("nullbytecert.pem")
++TALOS_INVALID_CRLDP = data_file("talos-2019-0758.pem")
+ DHFILE = data_file("ffdh3072.pem")
+ BYTES_DHFILE = DHFILE.encode(sys.getfilesystemencoding())
+@@ -227,6 +228,27 @@ class BasicSocketTests(unittest.TestCase):
+         self.assertEqual(p['crlDistributionPoints'],
+                          ('http://SVRIntl-G3-crl.verisign.com/SVRIntlG3.crl',))
++    def test_parse_cert_CVE_2019_5010(self):
++        p = ssl._ssl._test_decode_cert(TALOS_INVALID_CRLDP)
++        if support.verbose:
++            sys.stdout.write("\n" + pprint.pformat(p) + "\n")
++        self.assertEqual(
++            p,
++            {
++                'issuer': (
++                    (('countryName', 'UK'),), (('commonName', 'cody-ca'),)),
++                'notAfter': 'Jun 14 18:00:58 2028 GMT',
++                'notBefore': 'Jun 18 18:00:58 2018 GMT',
++                'serialNumber': '02',
++                'subject': ((('countryName', 'UK'),),
++                            (('commonName',
++                              'codenomicon-vm-2.test.lal.cisco.com'),)),
++                'subjectAltName': (
++                    ('DNS', 'codenomicon-vm-2.test.lal.cisco.com'),),
++                'version': 3
++            }
++        )
++
+     def test_parse_cert_CVE_2013_4238(self):
+         p = ssl._ssl._test_decode_cert(NULLBYTECERT)
+         if support.verbose:
+diff --git a/Misc/NEWS.d/next/Security/2019-01-15-18-16-05.bpo-35746.nMSd0j.rst b/Misc/NEWS.d/next/Security/2019-01-15-18-16-05.bpo-35746.nMSd0j.rst
+new file mode 100644
+index 0000000000..dffe347eec
+--- /dev/null
++++ b/Misc/NEWS.d/next/Security/2019-01-15-18-16-05.bpo-35746.nMSd0j.rst
+@@ -0,0 +1,3 @@
++[CVE-2019-5010] Fix a NULL pointer deref in ssl module. The cert parser did
++not handle CRL distribution points with empty DP or URI correctly. A
++malicious or buggy certificate can result into segfault.
+diff --git a/Modules/_ssl.c b/Modules/_ssl.c
+index a96c419260..19bb1207b4 100644
+--- a/Modules/_ssl.c
++++ b/Modules/_ssl.c
+@@ -1223,6 +1223,10 @@ _get_crl_dp(X509 *certificate) {
+         STACK_OF(GENERAL_NAME) *gns;
+         dp = sk_DIST_POINT_value(dps, i);
++        if (dp->distpoint == NULL) {
++            /* Ignore empty DP value, CVE-2019-5010 */
++            continue;
++        }
+         gns = dp->distpoint->name.fullname;
+         for (j=0; j < sk_GENERAL_NAME_num(gns); j++) {
+-- 
+2.11.0
+