upstream: Don't reply to PING in preauth phase or during KEX

Reported by the Qualys Security Advisory team. ok markus@

OpenBSD-Commit-ID: c656ac4abd1504389d1733d85152044b15830217

diff --git a/packet.c b/packet.c
index 486f8515746eb97324cd607326580c53fda6d1cf..9dea2cfc5188fb27c4ed6ebed0365defeae8a62e 100644 (file)
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.317 2024/08/23 04:51:00 deraadt Exp $ */
+/* $OpenBSD: packet.c,v 1.318 2025/02/18 08:02:12 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1864,6 +1864,14 @@ ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
                        if ((r = sshpkt_get_string_direct(ssh, &d, &len)) != 0)
                                return r;
                        DBG(debug("Received SSH2_MSG_PING len %zu", len));
+                       if (!ssh->state->after_authentication) {
+                               DBG(debug("Won't reply to PING in preauth"));
+                               break;
+                       }
+                       if (ssh_packet_is_rekeying(ssh)) {
+                               DBG(debug("Won't reply to PING during KEX"));
+                               break;
+                       }
                        if ((r = sshpkt_start(ssh, SSH2_MSG_PONG)) != 0 ||
                            (r = sshpkt_put_string(ssh, d, len)) != 0 ||
                            (r = sshpkt_send(ssh)) != 0)