CVE-2020-25719 s4:kdc: Check if the pac is valid before updating it

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14561

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/selftest/knownfail_heimdal_kdc b/selftest/knownfail_heimdal_kdc
index 850346940ad43d0d2c623cb7843b2ef46f347821..75ca4bba8c4d108b9ff906cf3a1bad5614123a43 100644 (file)
--- a/selftest/knownfail_heimdal_kdc
+++ b/selftest/knownfail_heimdal_kdc
@@ -271,13 +271,6 @@
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_remove_pac_service_no_auth_data_required
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_request_no_pac
 #
-# Alias tests
-#
-^samba.tests.krb5.alias_tests.samba.tests.krb5.alias_tests.AliasTests.test_create_alias_delete
-^samba.tests.krb5.alias_tests.samba.tests.krb5.alias_tests.AliasTests.test_create_alias_rename
-^samba.tests.krb5.alias_tests.samba.tests.krb5.alias_tests.AliasTests.test_dc_alias_delete
-^samba.tests.krb5.alias_tests.samba.tests.krb5.alias_tests.AliasTests.test_dc_alias_rename
-#
 # KDC TGT tests
 #
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_authdata_no_pac
@@ -288,10 +281,6 @@
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_no_partial_secrets
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_not_allowed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_not_revealed
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_authdata_no_pac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_no_pac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_rodc_allowed_denied
@@ -300,10 +289,6 @@
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_rodc_no_partial_secrets
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_rodc_not_allowed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_rodc_not_revealed
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_rodc_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_authdata_no_pac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_no_pac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_allowed_denied
@@ -312,10 +297,6 @@
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_no_partial_secrets
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_not_allowed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_not_revealed
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_upn_dns_info_ex_mac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_upn_dns_info_ex_upn_mac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_upn_dns_info_ex_upn_user
@@ -354,10 +335,6 @@
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_no_partial_secrets
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_not_allowed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_not_revealed
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_sid_mismatch_nonexisting
 #
 # PAC attributes tests
 #
@@ -392,8 +369,8 @@
 # PAC requester SID tests
 #
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_as_requester_sid
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_only_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_only_sid_mismatch_nonexisting
+^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_sid_mismatch_existing
+^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_requester_sid_mismatch_existing
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_requester_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_req_from_rodc_no_requester_sid
@@ -402,8 +379,8 @@
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_requester_sid_missing_rodc_renew
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_requester_sid_renew
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_requester_sid_rodc_renew
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_logon_info_only_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_logon_info_only_sid_mismatch_nonexisting
+^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_logon_info_sid_mismatch_existing
+^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_logon_info_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_requester_sid_mismatch_existing
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_requester_sid_mismatch_nonexisting
 #

diff --git a/selftest/knownfail_mit_kdc b/selftest/knownfail_mit_kdc
index 53aa05814c2702b81a6e6f495cf3a160b7e10800..dfdd17c655a325c0a8090a1b4d0c2597d945acf5 100644 (file)
--- a/selftest/knownfail_mit_kdc
+++ b/selftest/knownfail_mit_kdc
@@ -407,8 +407,6 @@ samba.tests.krb5.as_canonicalization_tests.samba.tests.krb5.as_canonicalization_
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_revealed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_sid_mismatch_existing
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_renew_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_authdata_no_pac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_no_pac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_s4u2self_req
@@ -434,8 +432,6 @@ samba.tests.krb5.as_canonicalization_tests.samba.tests.krb5.as_canonicalization_
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_revealed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_sid_mismatch_existing
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_upn_dns_info_ex_mac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_upn_dns_info_ex_upn_mac
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_upn_dns_info_ex_upn_user
@@ -475,8 +471,6 @@ samba.tests.krb5.as_canonicalization_tests.samba.tests.krb5.as_canonicalization_
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_revealed
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_sid_mismatch_existing
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_rodc_sid_mismatch_nonexisting
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_validate_sid_mismatch_nonexisting
 #
 # PAC attributes tests
 #
@@ -518,8 +512,8 @@ samba.tests.krb5.as_canonicalization_tests.samba.tests.krb5.as_canonicalization_
 # PAC requester SID tests
 #
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_as_requester_sid
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_only_sid_mismatch_existing
-^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_only_sid_mismatch_nonexisting
+^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_sid_mismatch_existing
+^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_logon_info_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_requester_sid_mismatch_existing
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_requester_sid_mismatch_nonexisting
 ^samba.tests.krb5.kdc_tgs_tests.samba.tests.krb5.kdc_tgs_tests.KdcTgsTests.test_tgs_req_from_rodc_no_requester_sid

diff --git a/source4/kdc/mit_samba.c b/source4/kdc/mit_samba.c
index d0e68ec8ea494d3bc84911330b919cb0511c5d92..592f6a3bac471aaa1fd92241f72a91638cef94ce 100644 (file)
--- a/source4/kdc/mit_samba.c
+++ b/source4/kdc/mit_samba.c
@@ -512,6 +512,15 @@ krb5_error_code mit_samba_reget_pac(struct mit_samba_context *ctx,
                client_skdc_entry =
                        talloc_get_type_abort(client->e_data,
                                              struct samba_kdc_entry);
+
+               /*
+                * Check the objectSID of the client and pac data are the same.
+                * Does a parse and SID check, but no crypto.
+                */
+               code = samba_kdc_validate_pac_blob(context, client_skdc_entry, *pac);
+               if (code != 0) {
+                       goto done;
+               }
        }
 
        if (server == NULL) {

diff --git a/source4/kdc/wdc-samba4.c b/source4/kdc/wdc-samba4.c
index ac9d7d51733893c352e713e0fd0035a56a60bd8b..ed6e9fb9b6338bbacbdc626e6c88a173883723b5 100644 (file)
--- a/source4/kdc/wdc-samba4.c
+++ b/source4/kdc/wdc-samba4.c
@@ -137,6 +137,23 @@ static krb5_error_code samba_wdc_reget_pac2(krb5_context context,
                return ENOMEM;
        }
 
+       if (client != NULL) {
+               struct samba_kdc_entry *client_skdc_entry = NULL;
+
+               client_skdc_entry = talloc_get_type_abort(client->ctx,
+                                                         struct samba_kdc_entry);
+
+               /*
+                * Check the objectSID of the client and pac data are the same.
+                * Does a parse and SID check, but no crypto.
+                */
+               ret = samba_kdc_validate_pac_blob(context, client_skdc_entry, *pac);
+               if (ret != 0) {
+                       talloc_free(mem_ctx);
+                       return ret;
+               }
+       }
+
        /* If the krbtgt was generated by an RODC, and we are not that
         * RODC, then we need to regenerate the PAC - we can't trust
         * it */