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$NetBSD: patch-CVE-2017-14176,v 1.1 2018/01/09 22:18:57 tez Exp $
Patch for CVE-2017-14176 from http://bazaar.launchpad.net/~brz/brz/trunk/revision/6754
--- bzrlib/transport/ssh.py.orig 2013-07-27 11:50:53.000000000 +0000
+++ bzrlib/transport/ssh.py
@@ -45,6 +45,10 @@ else:
from paramiko.sftp_client import SFTPClient
+class StrangeHostname(errors.BzrError):
+ _fmt = "Refusing to connect to strange SSH hostname %(hostname)s"
+
+
SYSTEM_HOSTKEYS = {}
BZR_HOSTKEYS = {}
@@ -359,6 +363,11 @@ class SubprocessVendor(SSHVendor):
# tests, but beware of using PIPE which may hang due to not being read.
_stderr_target = None
+ @staticmethod
+ def _check_hostname(arg):
+ if arg.startswith('-'):
+ raise StrangeHostname(hostname=arg)
+
def _connect(self, argv):
# Attempt to make a socketpair to use as stdin/stdout for the SSH
# subprocess. We prefer sockets to pipes because they support
@@ -423,9 +432,9 @@ class OpenSSHSubprocessVendor(Subprocess
if username is not None:
args.extend(['-l', username])
if subsystem is not None:
- args.extend(['-s', host, subsystem])
+ args.extend(['-s', '--', host, subsystem])
else:
- args.extend([host] + command)
+ args.extend(['--', host] + command)
return args
register_ssh_vendor('openssh', OpenSSHSubprocessVendor())
@@ -438,6 +447,7 @@ class SSHCorpSubprocessVendor(Subprocess
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
command=None):
+ self._check_hostname(host)
args = [self.executable_path, '-x']
if port is not None:
args.extend(['-p', str(port)])
@@ -459,6 +469,7 @@ class LSHSubprocessVendor(SubprocessVend
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
command=None):
+ self._check_hostname(host)
args = [self.executable_path]
if port is not None:
args.extend(['-p', str(port)])
@@ -480,6 +491,7 @@ class PLinkSubprocessVendor(SubprocessVe
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
command=None):
+ self._check_hostname(host)
args = [self.executable_path, '-x', '-a', '-ssh', '-2', '-batch']
if port is not None:
args.extend(['-P', str(port)])
--- bzrlib/tests/test_ssh_transport.py.orig 2013-07-27 11:50:53.000000000 +0000
+++ bzrlib/tests/test_ssh_transport.py
@@ -22,6 +22,7 @@ from bzrlib.transport.ssh import (
SSHCorpSubprocessVendor,
LSHSubprocessVendor,
SSHVendorManager,
+ StrangeHostname,
)
@@ -161,6 +162,19 @@ class SSHVendorManagerTests(TestCase):
class SubprocessVendorsTests(TestCase):
+ def test_openssh_command_tricked(self):
+ vendor = OpenSSHSubprocessVendor()
+ self.assertEqual(
+ vendor._get_vendor_specific_argv(
+ "user", "-oProxyCommand=blah", 100, command=["bzr"]),
+ ["ssh", "-oForwardX11=no", "-oForwardAgent=no",
+ "-oClearAllForwardings=yes",
+ "-oNoHostAuthenticationForLocalhost=yes",
+ "-p", "100",
+ "-l", "user",
+ "--",
+ "-oProxyCommand=blah", "bzr"])
+
def test_openssh_command_arguments(self):
vendor = OpenSSHSubprocessVendor()
self.assertEqual(
@@ -171,6 +185,7 @@ class SubprocessVendorsTests(TestCase):
"-oNoHostAuthenticationForLocalhost=yes",
"-p", "100",
"-l", "user",
+ "--",
"host", "bzr"]
)
@@ -184,9 +199,16 @@ class SubprocessVendorsTests(TestCase):
"-oNoHostAuthenticationForLocalhost=yes",
"-p", "100",
"-l", "user",
- "-s", "host", "sftp"]
+ "-s", "--", "host", "sftp"]
)
+ def test_openssh_command_tricked(self):
+ vendor = SSHCorpSubprocessVendor()
+ self.assertRaises(
+ StrangeHostname,
+ vendor._get_vendor_specific_argv,
+ "user", "-oProxyCommand=host", 100, command=["bzr"])
+
def test_sshcorp_command_arguments(self):
vendor = SSHCorpSubprocessVendor()
self.assertEqual(
@@ -209,6 +231,13 @@ class SubprocessVendorsTests(TestCase):
"-s", "sftp", "host"]
)
+ def test_lsh_command_tricked(self):
+ vendor = LSHSubprocessVendor()
+ self.assertRaises(
+ StrangeHostname,
+ vendor._get_vendor_specific_argv,
+ "user", "-oProxyCommand=host", 100, command=["bzr"])
+
def test_lsh_command_arguments(self):
vendor = LSHSubprocessVendor()
self.assertEqual(
@@ -231,6 +260,13 @@ class SubprocessVendorsTests(TestCase):
"--subsystem", "sftp", "host"]
)
+ def test_plink_command_tricked(self):
+ vendor = PLinkSubprocessVendor()
+ self.assertRaises(
+ StrangeHostname,
+ vendor._get_vendor_specific_argv,
+ "user", "-oProxyCommand=host", 100, command=["bzr"])
+
def test_plink_command_arguments(self):
vendor = PLinkSubprocessVendor()
self.assertEqual(
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