From 31c16d62fc762ab87e66e7f47e36dbfcfc8b5224 Mon Sep 17 00:00:00 2001 From: Xtreak Date: Sun, 17 Mar 2019 05:33:39 +0530 Subject: [PATCH] [3.5] bpo-35121: prefix dot in domain for proper subdomain validation (GH-10258) (#12281) Don't send cookies of domain A without Domain attribute to domain B when domain A is a suffix match of domain B while using a cookiejar with `http.cookiejar.DefaultCookiePolicy` policy. Patch by Karthikeyan Singaravelan. (cherry picked from commit ca7fe5063593958e5efdf90f068582837f07bd14) Co-authored-by: Xtreak CVE: CVE-2018-20852 Upstream-Status: Backport [https://github.com/python/cpython/commit/4749f1b69000259e23b4cc6f63c542a9bdc62f1b] Signed-off-by: Dan Tran --- Lib/http/cookiejar.py | 13 ++++++-- Lib/test/test_http_cookiejar.py | 30 +++++++++++++++++++ .../2018-10-31-15-39-17.bpo-35121.EgHv9k.rst | 4 +++ 3 files changed, 45 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Security/2018-10-31-15-39-17.bpo-35121.EgHv9k.rst diff --git a/Lib/http/cookiejar.py b/Lib/http/cookiejar.py index 6d4572af03..1cc9378ae4 100644 --- a/Lib/http/cookiejar.py +++ b/Lib/http/cookiejar.py @@ -1148,6 +1148,11 @@ class DefaultCookiePolicy(CookiePolicy): req_host, erhn = eff_request_host(request) domain = cookie.domain + if domain and not domain.startswith("."): + dotdomain = "." + domain + else: + dotdomain = domain + # strict check of non-domain cookies: Mozilla does this, MSIE5 doesn't if (cookie.version == 0 and (self.strict_ns_domain & self.DomainStrictNonDomain) and @@ -1160,7 +1165,7 @@ class DefaultCookiePolicy(CookiePolicy): _debug(" effective request-host name %s does not domain-match " "RFC 2965 cookie domain %s", erhn, domain) return False - if cookie.version == 0 and not ("."+erhn).endswith(domain): + if cookie.version == 0 and not ("."+erhn).endswith(dotdomain): _debug(" request-host %s does not match Netscape cookie domain " "%s", req_host, domain) return False @@ -1174,7 +1179,11 @@ class DefaultCookiePolicy(CookiePolicy): req_host = "."+req_host if not erhn.startswith("."): erhn = "."+erhn - if not (req_host.endswith(domain) or erhn.endswith(domain)): + if domain and not domain.startswith("."): + dotdomain = "." + domain + else: + dotdomain = domain + if not (req_host.endswith(dotdomain) or erhn.endswith(dotdomain)): #_debug(" request domain %s does not match cookie domain %s", # req_host, domain) return False diff --git a/Lib/test/test_http_cookiejar.py b/Lib/test/test_http_cookiejar.py index 49c01ae489..e67e6ae780 100644 --- a/Lib/test/test_http_cookiejar.py +++ b/Lib/test/test_http_cookiejar.py @@ -417,6 +417,7 @@ class CookieTests(unittest.TestCase): ("http://foo.bar.com/", ".foo.bar.com", True), ("http://foo.bar.com/", "foo.bar.com", True), ("http://foo.bar.com/", ".bar.com", True), + ("http://foo.bar.com/", "bar.com", True), ("http://foo.bar.com/", "com", True), ("http://foo.com/", "rhubarb.foo.com", False), ("http://foo.com/", ".foo.com", True), @@ -427,6 +428,8 @@ class CookieTests(unittest.TestCase): ("http://foo/", "foo", True), ("http://foo/", "foo.local", True), ("http://foo/", ".local", True), + ("http://barfoo.com", ".foo.com", False), + ("http://barfoo.com", "foo.com", False), ]: request = urllib.request.Request(url) r = pol.domain_return_ok(domain, request) @@ -961,6 +964,33 @@ class CookieTests(unittest.TestCase): c.add_cookie_header(req) self.assertFalse(req.has_header("Cookie")) + c.clear() + + pol.set_blocked_domains([]) + req = urllib.request.Request("http://acme.com/") + res = FakeResponse(headers, "http://acme.com/") + cookies = c.make_cookies(res, req) + c.extract_cookies(res, req) + self.assertEqual(len(c), 1) + + req = urllib.request.Request("http://acme.com/") + c.add_cookie_header(req) + self.assertTrue(req.has_header("Cookie")) + + req = urllib.request.Request("http://badacme.com/") + c.add_cookie_header(req) + self.assertFalse(pol.return_ok(cookies[0], req)) + self.assertFalse(req.has_header("Cookie")) + + p = pol.set_blocked_domains(["acme.com"]) + req = urllib.request.Request("http://acme.com/") + c.add_cookie_header(req) + self.assertFalse(req.has_header("Cookie")) + + req = urllib.request.Request("http://badacme.com/") + c.add_cookie_header(req) + self.assertFalse(req.has_header("Cookie")) + def test_secure(self): for ns in True, False: for whitespace in " ", "": diff --git a/Misc/NEWS.d/next/Security/2018-10-31-15-39-17.bpo-35121.EgHv9k.rst b/Misc/NEWS.d/next/Security/2018-10-31-15-39-17.bpo-35121.EgHv9k.rst new file mode 100644 index 0000000000..d2eb8f1f35 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2018-10-31-15-39-17.bpo-35121.EgHv9k.rst @@ -0,0 +1,4 @@ +Don't send cookies of domain A without Domain attribute to domain B +when domain A is a suffix match of domain B while using a cookiejar +with :class:`http.cookiejar.DefaultCookiePolicy` policy. Patch by +Karthikeyan Singaravelan. -- 2.22.0.vfs.1.1.57.gbaf16c8