From 59346084f64e90fdc48d31f60323abc9b576f790 Mon Sep 17 00:00:00 2001 From: Zoltan Fridrich Date: Mon, 16 Mar 2026 16:28:51 +0100 Subject: [PATCH] Fix CVE-2026-3497 Fix information disclosure or denial of service due to uninitialized variables in gssapi-keyex Resolves: RHEL-155825 Signed-off-by: Zoltan Fridrich --- openssh-9.6p1-gssapi-keyex.patch | 40 +++++++++++++++++--------------- openssh.spec | 7 +++++- 2 files changed, 27 insertions(+), 20 deletions(-) diff --git a/openssh-9.6p1-gssapi-keyex.patch b/openssh-9.6p1-gssapi-keyex.patch index ef1f97e..16892ac 100644 --- a/openssh-9.6p1-gssapi-keyex.patch +++ b/openssh-9.6p1-gssapi-keyex.patch @@ -1240,7 +1240,7 @@ diff --color -ruNp a/kexgen.c b/kexgen.c const struct sshbuf *client_version, diff --color -ruNp a/kexgssc.c b/kexgssc.c --- a/kexgssc.c 1970-01-01 01:00:00.000000000 +0100 -+++ b/kexgssc.c 2024-10-14 15:18:02.491798105 +0200 ++++ b/kexgssc.c 2026-03-13 12:25:23.115812190 +0100 @@ -0,0 +1,706 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. @@ -1369,7 +1369,7 @@ diff --color -ruNp a/kexgssc.c b/kexgssc.c + + /* Verify that the hash matches the MIC we just got. */ + if (GSS_ERROR(ssh_gssapi_checkmic(gss, &gss->buf, &gss->msg_tok))) -+ sshpkt_disconnect(ssh, "Hash's MIC didn't verify"); ++ ssh_packet_disconnect(ssh, "Hash's MIC didn't verify"); + + gss_release_buffer(&gss->minor, &gss->msg_tok); + @@ -1592,10 +1592,10 @@ diff --color -ruNp a/kexgssc.c b/kexgssc.c + fatal("Failed to read token: %s", ssh_err(r)); + /* If we're already complete - protocol error */ + if (gss->major == GSS_S_COMPLETE) -+ sshpkt_disconnect(ssh, "Protocol error: received token when complete"); ++ ssh_packet_disconnect(ssh, "Protocol error: received token when complete"); + } else { + if (gss->major != GSS_S_COMPLETE) -+ sshpkt_disconnect(ssh, "Protocol error: did not receive final token"); ++ ssh_packet_disconnect(ssh, "Protocol error: did not receive final token"); + } + if ((r = sshpkt_get_end(ssh)) != 0) + fatal("Expecting end of packet."); @@ -1731,7 +1731,7 @@ diff --color -ruNp a/kexgssc.c b/kexgssc.c + + /* Verify that the hash matches the MIC we just got. */ + if (GSS_ERROR(ssh_gssapi_checkmic(gss, &gss->buf, &gss->msg_tok))) -+ sshpkt_disconnect(ssh, "Hash's MIC didn't verify"); ++ ssh_packet_disconnect(ssh, "Hash's MIC didn't verify"); + + gss_release_buffer(&gss->minor, &gss->msg_tok); + @@ -1932,10 +1932,10 @@ diff --color -ruNp a/kexgssc.c b/kexgssc.c + fatal("Failed to read token: %s", ssh_err(r)); + /* If we're already complete - protocol error */ + if (gss->major == GSS_S_COMPLETE) -+ sshpkt_disconnect(ssh, "Protocol error: received token when complete"); ++ ssh_packet_disconnect(ssh, "Protocol error: received token when complete"); + } else { + if (gss->major != GSS_S_COMPLETE) -+ sshpkt_disconnect(ssh, "Protocol error: did not receive final token"); ++ ssh_packet_disconnect(ssh, "Protocol error: did not receive final token"); + } + if ((r = sshpkt_get_end(ssh)) != 0) + fatal("Expecting end of packet."); @@ -1950,8 +1950,8 @@ diff --color -ruNp a/kexgssc.c b/kexgssc.c +#endif /* defined(GSSAPI) && defined(WITH_OPENSSL) */ diff --color -ruNp a/kexgsss.c b/kexgsss.c --- a/kexgsss.c 1970-01-01 01:00:00.000000000 +0100 -+++ b/kexgsss.c 2024-10-14 15:18:02.491798105 +0200 -@@ -0,0 +1,601 @@ ++++ b/kexgsss.c 2026-03-13 12:32:17.556172591 +0100 +@@ -0,0 +1,603 @@ +/* + * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved. + * @@ -2083,7 +2083,7 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c +{ + struct kex *kex = ssh->kex; + Gssctxt *gss = kex->gss; -+ gss_buffer_desc msg_tok; ++ gss_buffer_desc msg_tok = GSS_C_EMPTY_BUFFER; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + struct sshbuf *shared_secret = NULL; @@ -2167,7 +2167,8 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c + Gssctxt *gss = kex->gss; + struct sshbuf *empty; + struct sshbuf *client_pubkey = NULL; -+ gss_buffer_desc recv_tok, send_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc recv_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + OM_uint32 ret_flags = 0; + int r; + @@ -2243,7 +2244,8 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c + struct ssh *ssh) +{ + Gssctxt *gss = ssh->kex->gss; -+ gss_buffer_desc recv_tok, send_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc recv_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + OM_uint32 ret_flags = 0; + int r; + @@ -2334,7 +2336,7 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c +{ + struct kex *kex = ssh->kex; + Gssctxt *gss = kex->gss; -+ gss_buffer_desc msg_tok; ++ gss_buffer_desc msg_tok = GSS_C_EMPTY_BUFFER; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t hashlen; + const BIGNUM *pub_key, *dh_p, *dh_g; @@ -2475,10 +2477,8 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c + fatal("GSS_GEX, bad parameters: %d !< %d !< %d", min, nbits, max); + + kex->dh = mm_choose_dh(min, nbits, max); -+ if (kex->dh == NULL) { -+ sshpkt_disconnect(ssh, "Protocol error: no matching group found"); -+ fatal("Protocol error: no matching group found"); -+ } ++ if (kex->dh == NULL) ++ ssh_packet_disconnect(ssh, "Protocol error: no matching group found"); + + DH_get0_pqg(kex->dh, &dh_p, NULL, &dh_g); + if ((r = sshpkt_start(ssh, SSH2_MSG_KEXGSS_GROUP)) != 0 || @@ -2510,7 +2510,8 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c + struct ssh *ssh) +{ + Gssctxt *gss = ssh->kex->gss; -+ gss_buffer_desc recv_tok, send_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc recv_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + OM_uint32 ret_flags = 0; + int r; + @@ -2537,7 +2538,8 @@ diff --color -ruNp a/kexgsss.c b/kexgsss.c + struct ssh *ssh) +{ + Gssctxt *gss = ssh->kex->gss; -+ gss_buffer_desc recv_tok, send_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc recv_tok = GSS_C_EMPTY_BUFFER; ++ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + OM_uint32 ret_flags = 0; + int r; + diff --git a/openssh.spec b/openssh.spec index 5477a86..e3fffe7 100644 --- a/openssh.spec +++ b/openssh.spec @@ -47,7 +47,7 @@ # Do not forget to bump pam_ssh_agent_auth release if you rewind the main package release to 1 %global openssh_ver 9.9p1 -%global openssh_rel 4 +%global openssh_rel 5 %global pam_ssh_agent_ver 0.10.4 %global pam_ssh_agent_rel 7 @@ -748,6 +748,11 @@ test -f %{sysconfig_anaconda} && \ %endif %changelog +* Mon Mar 16 2026 Zoltan Fridrich - 9.9p1-5 +- CVE-2026-3497: Fix information disclosure or denial of service due + to uninitialized variables in gssapi-keyex + Resolves: RHEL-155825 + * Wed Feb 25 2026 Dmitry Belyavskiy - 9.9p1-4 - Provide a way to skip unsupported ML-KEM hybrid algorithms in FIPS mode Resolves: RHEL-151580