untrusted comment: verify with openbsd-75-base.pub
RWRGj1pRpprAfqoQow3N+KWimaeO6ZSsro8ODIZB5gbbZ4r08q9m5AMYJ4O+nCX4gqaihBSk6rnGvyBlEHwAYRWuEjUUUNplkgQ=
OpenBSD 7.5 errata 017, February 18, 2025:
sshd(8) denial of service relating to SSH2_MSG_PING handling.
ssh(1) server impersonation when VerifyHostKeyDNS enabled.
Apply by doing:
signify -Vep /etc/signify/openbsd-75-base.pub -x 017_ssh.patch.sig \
-m - | (cd /usr/src && patch -p0)
And then rebuild and install OpenSSH:
cd /usr/src/usr.bin/ssh
make obj
make
make install
Index: usr.bin/ssh/krl.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/krl.c,v
diff -u -p -r1.59 krl.c
--- usr.bin/ssh/krl.c 17 Jul 2023 05:22:30 -0000 1.59
+++ usr.bin/ssh/krl.c 7 Feb 2025 17:28:59 -0000
@@ -672,6 +672,7 @@ revoked_certs_generate(struct revoked_ce
break;
case KRL_SECTION_CERT_SERIAL_BITMAP:
if (rs->lo - bitmap_start > INT_MAX) {
+ r = SSH_ERR_INVALID_FORMAT;
error_f("insane bitmap gap");
goto out;
}
@@ -1057,6 +1058,7 @@ ssh_krl_from_blob(struct sshbuf *buf, st
}
if ((krl = ssh_krl_init()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
error_f("alloc failed");
goto out;
}
Index: usr.bin/ssh/packet.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/packet.c,v
diff -u -p -r1.313 packet.c
--- usr.bin/ssh/packet.c 18 Dec 2023 14:45:17 -0000 1.313
+++ usr.bin/ssh/packet.c 7 Feb 2025 17:28:59 -0000
@@ -1752,6 +1752,14 @@ ssh_packet_read_poll_seqnr(struct ssh *s
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)
Index: usr.bin/ssh/ssh-agent.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/ssh-agent.c,v
diff -u -p -r1.306 ssh-agent.c
--- usr.bin/ssh/ssh-agent.c 9 Mar 2024 05:12:13 -0000 1.306
+++ usr.bin/ssh/ssh-agent.c 7 Feb 2025 17:28:59 -0000
@@ -1195,6 +1195,7 @@ parse_key_constraint_extension(struct ss
"
[email protected]") == 0) {
if (*dcsp != NULL) {
error_f("%s already set", ext_name);
+ r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if ((r = sshbuf_froms(m, &b)) != 0) {
@@ -1204,6 +1205,7 @@ parse_key_constraint_extension(struct ss
while (sshbuf_len(b) != 0) {
if (*ndcsp >= AGENT_MAX_DEST_CONSTRAINTS) {
error_f("too many %s constraints", ext_name);
+ r = SSH_ERR_INVALID_FORMAT;
goto out;
}
*dcsp = xrecallocarray(*dcsp, *ndcsp, *ndcsp + 1,
@@ -1221,6 +1223,7 @@ parse_key_constraint_extension(struct ss
}
if (*certs != NULL) {
error_f("%s already set", ext_name);
+ r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if ((r = sshbuf_get_u8(m, &v)) != 0 ||
@@ -1232,6 +1235,7 @@ parse_key_constraint_extension(struct ss
while (sshbuf_len(b) != 0) {
if (*ncerts >= AGENT_MAX_EXT_CERTS) {
error_f("too many %s constraints", ext_name);
+ r = SSH_ERR_INVALID_FORMAT;
goto out;
}
*certs = xrecallocarray(*certs, *ncerts, *ncerts + 1,
@@ -1728,6 +1732,7 @@ process_ext_session_bind(SocketEntry *e)
/* record new key/sid */
if (e->nsession_ids >= AGENT_MAX_SESSION_IDS) {
error_f("too many session IDs recorded");
+ r = -1;
goto out;
}
e->session_ids = xrecallocarray(e->session_ids, e->nsession_ids,
Index: usr.bin/ssh/ssh-sk-client.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/ssh-sk-client.c,v
diff -u -p -r1.12 ssh-sk-client.c
--- usr.bin/ssh/ssh-sk-client.c 14 Jan 2022 03:34:00 -0000 1.12
+++ usr.bin/ssh/ssh-sk-client.c 7 Feb 2025 17:28:59 -0000
@@ -429,6 +429,7 @@ sshsk_load_resident(const char *provider
}
if ((srk = calloc(1, sizeof(*srk))) == NULL) {
error_f("calloc failed");
+ r = SSH_ERR_ALLOC_FAIL;
goto out;
}
srk->key = key;
@@ -440,6 +441,7 @@ sshsk_load_resident(const char *provider
if ((tmp = recallocarray(srks, nsrks, nsrks + 1,
sizeof(*srks))) == NULL) {
error_f("recallocarray keys failed");
+ r = SSH_ERR_ALLOC_FAIL;
goto out;
}
debug_f("srks[%zu]: %s %s uidlen %zu", nsrks,
Index: usr.bin/ssh/sshconnect2.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/sshconnect2.c,v
diff -u -p -r1.372 sshconnect2.c
--- usr.bin/ssh/sshconnect2.c 8 Jan 2024 00:34:34 -0000 1.372
+++ usr.bin/ssh/sshconnect2.c 7 Feb 2025 17:29:00 -0000
@@ -96,7 +96,7 @@ verify_host_key_callback(struct sshkey *
options.required_rsa_size)) != 0)
fatal_r(r, "Bad server host key");
if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
- xxx_conn_info) == -1)
+ xxx_conn_info) != 0)
fatal("Host key verification failed.");
return 0;
}
@@ -693,6 +693,7 @@ input_userauth_pk_ok(int type, u_int32_t
if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
debug_f("server sent unknown pkalg %s", pkalg);
+ r = SSH_ERR_INVALID_FORMAT;
goto done;
}
if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
@@ -703,6 +704,7 @@ input_userauth_pk_ok(int type, u_int32_t
error("input_userauth_pk_ok: type mismatch "
"for decoded key (received %d, expected %d)",
key->type, pktype);
+ r = SSH_ERR_INVALID_FORMAT;
goto done;
}
@@ -722,6 +724,7 @@ input_userauth_pk_ok(int type, u_int32_t
SSH_FP_DEFAULT);
error_f("server replied with unknown key: %s %s",
sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
+ r = SSH_ERR_INVALID_FORMAT;
goto done;
}
ident = format_identity(id);
Index: usr.bin/ssh/sshsig.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/sshsig.c,v
diff -u -p -r1.35 sshsig.c
--- usr.bin/ssh/sshsig.c 8 Mar 2024 22:16:32 -0000 1.35
+++ usr.bin/ssh/sshsig.c 7 Feb 2025 17:29:00 -0000
@@ -872,6 +872,7 @@ cert_filter_principals(const char *path,
}
if ((principals = sshbuf_dup_string(nprincipals)) == NULL) {
error_f("buffer error");
+ r = SSH_ERR_ALLOC_FAIL;
goto out;
}
/* success */
