CVE-2020-25718 s4-rpc_server: Confirm that the RODC has the UF_PARTIAL_SECRETS_ACCOUN...

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14558

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Joseph Sutton <josephsutton@catalyst.net.nz>

diff --git a/source4/rpc_server/common/sid_helper.c b/source4/rpc_server/common/sid_helper.c
index ab2b4373b4734ad8b526a7d77913e4c8b98ed006..99c5fc20d9d50183383d956a78e9ba20a686dd96 100644 (file)
--- a/source4/rpc_server/common/sid_helper.c
+++ b/source4/rpc_server/common/sid_helper.c
@@ -141,6 +141,7 @@ WERROR samdb_confirm_rodc_allowed_to_repl_to_sid_list(struct ldb_context *sam_ct
        struct dom_sid *never_reveal_sids, *reveal_sids;
        TALLOC_CTX *frame = talloc_stackframe();
        WERROR werr;
+       uint32_t rodc_uac;
        
        /*
         * We are not allowed to get anyone elses krbtgt secrets (and
@@ -160,6 +161,18 @@ WERROR samdb_confirm_rodc_allowed_to_repl_to_sid_list(struct ldb_context *sam_ct
                return WERR_DS_DRA_SECRETS_DENIED;
        }
 
+       /* Be very sure the RODC is really an RODC */
+       rodc_uac = ldb_msg_find_attr_as_uint(rodc_msg,
+                                            "userAccountControl",
+                                            0);
+       if ((rodc_uac & UF_PARTIAL_SECRETS_ACCOUNT)
+           != UF_PARTIAL_SECRETS_ACCOUNT) {
+               TALLOC_FREE(frame);
+               DBG_ERR("Attempt to use an RODC account that is not an RODC: %s\n",
+                       ldb_dn_get_linearized(rodc_msg->dn));
+               return WERR_DS_DRA_SECRETS_DENIED;
+       }
+
        werr = samdb_result_sid_array_dn(sam_ctx, rodc_msg,
                                         frame, "msDS-NeverRevealGroup",
                                         &num_never_reveal_sids,

diff --git a/source4/rpc_server/drsuapi/getncchanges.c b/source4/rpc_server/drsuapi/getncchanges.c
index a9d305fc9a058b4238c38d3263b25f46e6886918..2fbd178cedca6c9c9eeca6370e571834eb09a821 100644 (file)
--- a/source4/rpc_server/drsuapi/getncchanges.c
+++ b/source4/rpc_server/drsuapi/getncchanges.c
@@ -1168,7 +1168,12 @@ static WERROR getncchanges_repl_secret(struct drsuapi_bind_state *b_state,
        struct ldb_dn *ntds_dn = NULL, *server_dn = NULL;
        struct ldb_dn *rodc_dn, *krbtgt_link_dn;
        int ret;
-       const char *rodc_attrs[] = { "msDS-KrbTgtLink", "msDS-NeverRevealGroup", "msDS-RevealOnDemandGroup", "objectGUID", NULL };
+       const char *rodc_attrs[] = { "msDS-KrbTgtLink",
+                                    "msDS-NeverRevealGroup",
+                                    "msDS-RevealOnDemandGroup",
+                                    "objectGUID",
+                                    "userAccountControl",
+                                    NULL };
        const char *obj_attrs[] = { "tokenGroups", "objectSid", "UserAccountControl", "msDS-KrbTgtLinkBL", NULL };
        struct ldb_result *rodc_res = NULL, *obj_res = NULL;
        uint32_t num_token_sids;

diff --git a/source4/rpc_server/netlogon/dcerpc_netlogon.c b/source4/rpc_server/netlogon/dcerpc_netlogon.c
index 0b8330b9f2182b8051fc800182024af0a6e62c1b..e3422d8b19f7c9e2e6007732157eb02ec1820a4f 100644 (file)
--- a/source4/rpc_server/netlogon/dcerpc_netlogon.c
+++ b/source4/rpc_server/netlogon/dcerpc_netlogon.c
@@ -2851,7 +2851,12 @@ static bool sam_rodc_access_check(struct ldb_context *sam_ctx,
                                  struct dom_sid *user_sid,
                                  struct ldb_dn *obj_dn)
 {
-       const char *rodc_attrs[] = { "msDS-KrbTgtLink", "msDS-NeverRevealGroup", "msDS-RevealOnDemandGroup", "objectGUID", NULL };
+       const char *rodc_attrs[] = { "msDS-KrbTgtLink",
+                                    "msDS-NeverRevealGroup",
+                                    "msDS-RevealOnDemandGroup",
+                                    "objectGUID",
+                                    "userAccountControl",
+                                    NULL };
        const char *obj_attrs[] = { "tokenGroups", "objectSid", "UserAccountControl", "msDS-KrbTgtLinkBL", NULL };
        struct ldb_dn *rodc_dn;
        int ret;