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
This commit is contained in:
parent
c9f872b0bd
commit
a37f52436f
|
@ -0,0 +1,22 @@
|
|||
-----BEGIN CERTIFICATE-----
|
||||
MIIDqDCCApKgAwIBAgIBAjALBgkqhkiG9w0BAQswHzELMAkGA1UEBhMCVUsxEDAO
|
||||
BgNVBAMTB2NvZHktY2EwHhcNMTgwNjE4MTgwMDU4WhcNMjgwNjE0MTgwMDU4WjA7
|
||||
MQswCQYDVQQGEwJVSzEsMCoGA1UEAxMjY29kZW5vbWljb24tdm0tMi50ZXN0Lmxh
|
||||
bC5jaXNjby5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQC63fGB
|
||||
J80A9Av1GB0bptslKRIUtJm8EeEu34HkDWbL6AJY0P8WfDtlXjlPaLqFa6sqH6ES
|
||||
V48prSm1ZUbDSVL8R6BYVYpOlK8/48xk4pGTgRzv69gf5SGtQLwHy8UPBKgjSZoD
|
||||
5a5k5wJXGswhKFFNqyyxqCvWmMnJWxXTt2XDCiWc4g4YAWi4O4+6SeeHVAV9rV7C
|
||||
1wxqjzKovVe2uZOHjKEzJbbIU6JBPb6TRfMdRdYOw98n1VXDcKVgdX2DuuqjCzHP
|
||||
WhU4Tw050M9NaK3eXp4Mh69VuiKoBGOLSOcS8reqHIU46Reg0hqeL8LIL6OhFHIF
|
||||
j7HR6V1X6F+BfRS/AgMBAAGjgdYwgdMwCQYDVR0TBAIwADAdBgNVHQ4EFgQUOktp
|
||||
HQjxDXXUg8prleY9jeLKeQ4wTwYDVR0jBEgwRoAUx6zgPygZ0ZErF9sPC4+5e2Io
|
||||
UU+hI6QhMB8xCzAJBgNVBAYTAlVLMRAwDgYDVQQDEwdjb2R5LWNhggkA1QEAuwb7
|
||||
2s0wCQYDVR0SBAIwADAuBgNVHREEJzAlgiNjb2Rlbm9taWNvbi12bS0yLnRlc3Qu
|
||||
bGFsLmNpc2NvLmNvbTAOBgNVHQ8BAf8EBAMCBaAwCwYDVR0fBAQwAjAAMAsGCSqG
|
||||
SIb3DQEBCwOCAQEAvqantx2yBlM11RoFiCfi+AfSblXPdrIrHvccepV4pYc/yO6p
|
||||
t1f2dxHQb8rWH3i6cWag/EgIZx+HJQvo0rgPY1BFJsX1WnYf1/znZpkUBGbVmlJr
|
||||
t/dW1gSkNS6sPsM0Q+7HPgEv8CPDNK5eo7vU2seE0iWOkxSyVUuiCEY9ZVGaLVit
|
||||
p0C78nZ35Pdv4I+1cosmHl28+es1WI22rrnmdBpH8J1eY6WvUw2xuZHLeNVN0TzV
|
||||
Q3qq53AaCWuLOD1AjESWuUCxMZTK9DPS4JKXTK8RLyDeqOvJGjsSWp3kL0y3GaQ+
|
||||
10T1rfkKJub2+m9A9duin1fn6tHc2wSvB7m3DA==
|
||||
-----END CERTIFICATE-----
|
|
@ -115,6 +115,7 @@ 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 = os.fsencode(DHFILE)
|
||||
|
@ -348,6 +349,27 @@ 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:
|
||||
|
|
|
@ -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.
|
|
@ -1515,6 +1515,10 @@ _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++) {
|
||||
|
|
Loading…
Reference in New Issue