diff --git a/Lib/netrc.py b/Lib/netrc.py
index 5493d77..0b4eedf 100644
--- a/Lib/netrc.py
+++ b/Lib/netrc.py
@@ -2,7 +2,7 @@
 
 # Module and documentation by Eric S. Raymond, 21 Dec 1998
 
-import os, shlex
+import os, stat, shlex, pwd
 
 __all__ = ["netrc", "NetrcParseError"]
 
@@ -21,6 +21,7 @@
 
 class netrc:
     def __init__(self, file=None):
+        default_netrc = file is None
         if file is None:
             try:
                 file = os.path.join(os.environ['HOME'], ".netrc")
@@ -77,6 +78,26 @@
                 elif tt == 'account':
                     account = lexer.get_token()
                 elif tt == 'password':
+                    if os.name == 'posix' and default_netrc:
+                        prop = os.fstat(fp.fileno())
+                        if prop.st_uid != os.getuid():
+                            try:
+                                fowner = pwd.getpwuid(prop.st_uid)[0]
+                            except KeyError:
+                                fowner = 'uid %s' % prop.st_uid
+                            try:
+                                user = pwd.getpwuid(os.getuid())[0]
+                            except KeyError:
+                                user = 'uid %s ' % os.getuid()
+                            raise NetrcParseError(
+                                ("~/.netrc file owner (%s) does not match"
+                                 " current user (%s)") % (fowner, user),
+                                file, lexer.lineno)
+                        if (prop.st_mode & (stat.S_IRWXG | stat.S_IRWXO)):
+                            raise NetrcParseError(
+                               "~/.netrc access too permissive: access"
+                               " permissions must restrict access to only"
+                               " the owner", file, lexer.lineno)
                     password = lexer.get_token()
                 else:
                     raise NetrcParseError("bad follower token %r" % tt,
diff --git a/Lib/test/test_netrc.py b/Lib/test/test_netrc.py
index b536255..24ad786 100644
--- a/Lib/test/test_netrc.py
+++ b/Lib/test/test_netrc.py
@@ -32,7 +32,7 @@
 
     def tearDown (self):
         del self.netrc
-        os.unlink(temp_filename)
+        test_support.unlink(temp_filename)
 
     def test_case_1(self):
         self.assert_(self.netrc.macros == {'macro1':['line1\n', 'line2\n'],
@@ -41,6 +41,27 @@
         self.assert_(self.netrc.hosts['foo'] == ('log1', 'acct1', 'pass1'))
         self.assert_(self.netrc.hosts['default'] == ('log2', None, 'pass2'))
 
+    if os.name == 'posix':
+        def test_security(self):
+            # This test is incomplete since we are normally not run as root and
+            # therefore can't test the file ownership being wrong.
+            os.unlink(temp_filename)
+            d = test_support.TESTFN
+            try:
+                os.mkdir(d)
+                fn = os.path.join(d, '.netrc')
+                with open(fn, 'wt') as f:
+                    f.write(TEST_NETRC)
+                with test_support.EnvironmentVarGuard() as environ:
+                    environ.set('HOME', d)
+                    os.chmod(fn, 0600)
+                    self.netrc = netrc.netrc()
+                    self.test_case_1()
+                    os.chmod(fn, 0622)
+                    self.assertRaises(netrc.NetrcParseError, netrc.netrc)
+            finally:
+                test_support.rmtree(d)
+
 def test_main():
     test_support.run_unittest(NetrcTestCase)