CVE-2020-25722 s4/dsdb/samldb: samldb_service_principal_names_change checks values

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14876

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c
index ec64e9ab6219961a13c673b1cf6ffa8a2d22f657..27385a0787a38e31cf80922d97aab26aa147dd1d 100644 (file)
--- a/source4/dsdb/samdb/ldb_modules/samldb.c
+++ b/source4/dsdb/samdb/ldb_modules/samldb.c
@@ -4052,10 +4052,22 @@ static int samldb_service_principal_names_change(struct samldb_ctx *ac)
        unsigned int i, j;
        int ret;
 
-       el = dsdb_get_single_valued_attr(ac->msg, "dNSHostName",
-                                        ac->req->operation);
-       el2 = dsdb_get_single_valued_attr(ac->msg, "sAMAccountName",
-                                         ac->req->operation);
+       ret = dsdb_get_expected_new_values(ac,
+                                          ac->msg,
+                                          "dNSHostName",
+                                          &el,
+                                          ac->req->operation);
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+       ret = dsdb_get_expected_new_values(ac,
+                                          ac->msg,
+                                          "sAMAccountName",
+                                          &el2,
+                                          ac->req->operation);
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
        if ((el == NULL) && (el2 == NULL)) {
                /* we are not affected */
                return LDB_SUCCESS;