don't accept modify operations with no modifications (ITS#4183)

diff --git a/servers/slapd/modify.c b/servers/slapd/modify.c
index 90c7d3c3a0901f60388365b006b26d5ae7511f27..c4e35be7aa2474b7a1fb0c6ad5a7dc3990d41c13 100644 (file)
--- a/servers/slapd/modify.c
+++ b/servers/slapd/modify.c
@@ -169,6 +169,14 @@ do_modify(
        }
        *modtail = NULL;
 
+       if ( modlist == NULL ) {
+               Debug( LDAP_DEBUG_ANY, "do_modify: no modifications\n", 0, 0, 0 );
+               send_ldap_error( op, rs, LDAP_PROTOCOL_ERROR,
+                       "empty change secquence in modify operation" );
+
+               goto cleanup;
+       }
+
        if( get_ctrls( op, rs, 1 ) != LDAP_SUCCESS ) {
                Debug( LDAP_DEBUG_ANY, "do_modify: get_ctrls failed\n", 0, 0, 0 );