diff --git a/src/libvirt.c b/src/libvirt.c
index 0f8d79a59be9c871769be085ae5df301ca848cdd..aec5d80fa4b746b5592da7e8e220f63ae1a8ba78 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -1135,6 +1135,12 @@ do_open(const char *name,
     if (name && name[0] == '\0')
         name = NULL;
 
+    if (!name && virIsSUID()) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("An explicit URI must be provided when setuid"));
+        goto failed;
+    }
+
     /*
      *  If no URI is passed, then check for an environment string if not
      *  available probe the compiled in drivers to find a default hypervisor
diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
index 43aaa82e8a9762870fc50e6249d4c3ba92741042..fd8eeb1b91e5195f72f1faf0fb961d11b4880d56 100644
--- a/src/remote/remote_driver.c
+++ b/src/remote/remote_driver.c
@@ -488,6 +488,20 @@ doRemoteOpen(virConnectPtr conn,
         transport = trans_unix;
     }
 
+    /*
+     * We don't want to be executing external programs in setuid mode,
+     * so this rules out 'ext' and 'ssh' transports. Exclude libssh
+     * and tls too, since we're not confident the libraries are safe
+     * for setuid usage. Just allow UNIX sockets, since that does
+     * not require any external libraries or command execution
+     */
+    if (virIsSUID() &&
+        transport != trans_unix) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Only Unix socket URI transport is allowed in setuid mode"));
+        return VIR_DRV_OPEN_ERROR;
+    }
+
     /* Local variables which we will initialize. These can
      * get freed in the failed: path.
      */