From 428ede3dd3bbf3bba86ca1b321bedfcc9aebba79 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Thu, 3 Nov 2016 17:16:43 +0100 Subject: [PATCH 1/9] CVE-2017-12150: s3:lib: get_cmdline_auth_info_signing_state smb_encrypt SMB_SIGNING_REQUIRED This is an addition to the fixes for CVE-2015-5296. It applies to smb2mount -e, smbcacls -e and smbcquotas -e. BUG: https://bugzilla.samba.org/show_bug.cgi?id=12997 Signed-off-by: Stefan Metzmacher --- source3/lib/util_cmdline.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/source3/lib/util_cmdline.c b/source3/lib/util_cmdline.c index 80c3ecdb462..539fa55d3a2 100644 --- a/source3/lib/util_cmdline.c +++ b/source3/lib/util_cmdline.c @@ -123,6 +123,9 @@ bool set_cmdline_auth_info_signing_state(struct user_auth_info *auth_info, int get_cmdline_auth_info_signing_state(const struct user_auth_info *auth_info) { + if (auth_info->smb_encrypt) { + return SMB_SIGNING_REQUIRED; + } return auth_info->signing_state; } -- 2.11.0 From 26b87d01b015c83a4670db62839f5c84b6e66478 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Fri, 9 Dec 2016 09:26:32 +0100 Subject: [PATCH 2/9] CVE-2017-12150: s3:pylibsmb: make use of SMB_SIGNING_DEFAULT for 'samba.samba3.libsmb_samba_internal' BUG: https://bugzilla.samba.org/show_bug.cgi?id=12997 Signed-off-by: Stefan Metzmacher --- source3/libsmb/pylibsmb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/source3/libsmb/pylibsmb.c b/source3/libsmb/pylibsmb.c index 0c5d7e94841..97aa39ebce9 100644 --- a/source3/libsmb/pylibsmb.c +++ b/source3/libsmb/pylibsmb.c @@ -447,7 +447,7 @@ static int py_cli_state_init(struct py_cli_state *self, PyObject *args, cli_credentials_get_username(cli_creds), cli_credentials_get_domain(cli_creds), cli_credentials_get_password(cli_creds), - 0, 0); + 0, SMB_SIGNING_DEFAULT); if (!py_tevent_req_wait_exc(self->ev, req)) { return -1; } -- 2.11.0 From 95f6e5b574856453c3ef36ebe9ae86d8456e6404 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Mon, 12 Dec 2016 05:49:46 +0100 Subject: [PATCH 3/9] CVE-2017-12150: libgpo: make use of SMB_SIGNING_REQUIRED in gpo_connect_server() It's important that we use a signed connection to get the GPOs! BUG: https://bugzilla.samba.org/show_bug.cgi?id=12997 Signed-off-by: Stefan Metzmacher --- libgpo/gpo_fetch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libgpo/gpo_fetch.c b/libgpo/gpo_fetch.c index 6b01544faee..cb969ff4270 100644 --- a/libgpo/gpo_fetch.c +++ b/libgpo/gpo_fetch.c @@ -133,7 +133,7 @@ static NTSTATUS gpo_connect_server(ADS_STRUCT *ads, ads->auth.password, CLI_FULL_CONNECTION_USE_KERBEROS | CLI_FULL_CONNECTION_FALLBACK_AFTER_KERBEROS, - Undefined); + SMB_SIGNING_REQUIRED); if (!NT_STATUS_IS_OK(result)) { DEBUG(10,("check_refresh_gpo: " "failed to connect: %s\n", -- 2.11.0 From b06322309752f3b666ad38f42ef2e96f1c41a24a Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Tue, 29 Aug 2017 15:24:14 +0200 Subject: [PATCH 4/9] CVE-2017-12150: auth/credentials: cli_credentials_authentication_requested() should check for NTLM_CCACHE/SIGN/SEAL BUG: https://bugzilla.samba.org/show_bug.cgi?id=12997 Signed-off-by: Stefan Metzmacher --- auth/credentials/credentials.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/auth/credentials/credentials.c b/auth/credentials/credentials.c index 3b7d42a29a5..43e587aa5a0 100644 --- a/auth/credentials/credentials.c +++ b/auth/credentials/credentials.c @@ -25,6 +25,7 @@ #include "librpc/gen_ndr/samr.h" /* for struct samrPassword */ #include "auth/credentials/credentials.h" #include "auth/credentials/credentials_internal.h" +#include "auth/gensec/gensec.h" #include "libcli/auth/libcli_auth.h" #include "tevent.h" #include "param/param.h" @@ -362,6 +363,8 @@ _PUBLIC_ bool cli_credentials_set_principal_callback(struct cli_credentials *cre _PUBLIC_ bool cli_credentials_authentication_requested(struct cli_credentials *cred) { + uint32_t gensec_features = 0; + if (cred->bind_dn) { return true; } @@ -389,6 +392,19 @@ _PUBLIC_ bool cli_credentials_authentication_requested(struct cli_credentials *c return true; } + gensec_features = cli_credentials_get_gensec_features(cred); + if (gensec_features & GENSEC_FEATURE_NTLM_CCACHE) { + return true; + } + + if (gensec_features & GENSEC_FEATURE_SIGN) { + return true; + } + + if (gensec_features & GENSEC_FEATURE_SEAL) { + return true; + } + return false; } -- 2.11.0 From 4a91f4ab82e3f729a12947ff65a74b072dd94acc Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Tue, 29 Aug 2017 15:35:49 +0200 Subject: [PATCH 5/9] CVE-2017-12150: libcli/smb: add smbXcli_conn_signing_mandatory() BUG: https://bugzilla.samba.org/show_bug.cgi?id=12997 Signed-off-by: Stefan Metzmacher --- libcli/smb/smbXcli_base.c | 5 +++++ libcli/smb/smbXcli_base.h | 1 + 2 files changed, 6 insertions(+) diff --git a/libcli/smb/smbXcli_base.c b/libcli/smb/smbXcli_base.c index 691b8ff263e..3c411276025 100644 --- a/libcli/smb/smbXcli_base.c +++ b/libcli/smb/smbXcli_base.c @@ -468,6 +468,11 @@ bool smbXcli_conn_use_unicode(struct smbXcli_conn *conn) return false; } +bool smbXcli_conn_signing_mandatory(struct smbXcli_conn *conn) +{ + return conn->mandatory_signing; +} + void smbXcli_conn_set_sockopt(struct smbXcli_conn *conn, const char *options) { set_socket_options(conn->sock_fd, options); diff --git a/libcli/smb/smbXcli_base.h b/libcli/smb/smbXcli_base.h index 16c8848dd12..6809807ac76 100644 --- a/libcli/smb/smbXcli_base.h +++ b/libcli/smb/smbXcli_base.h @@ -47,6 +47,7 @@ bool smbXcli_conn_dfs_supported(struct smbXcli_conn *conn); enum protocol_types smbXcli_conn_protocol(struct smbXcli_conn *conn); bool smbXcli_conn_use_unicode(struct smbXcli_conn *conn); +bool smbXcli_conn_signing_mandatory(struct smbXcli_conn *conn); void smbXcli_conn_set_sockopt(struct smbXcli_conn *conn, const char *options); const struct sockaddr_storage *smbXcli_conn_local_sockaddr(struct smbXcli_conn *conn); -- 2.11.0 From 81f1804d45c1b698ee87ee4d4c84197df98ea4f2 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Mon, 12 Dec 2016 06:07:56 +0100 Subject: [PATCH 6/9] CVE-2017-12150: s3:libsmb: only fallback to anonymous if authentication was not requested With forced encryption or required signing we should also don't fallback. BUG: https://bugzilla.samba.org/show_bug.cgi?id=12997 Signed-off-by: Stefan Metzmacher --- source3/libsmb/clidfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/source3/libsmb/clidfs.c b/source3/libsmb/clidfs.c index d2a4c194f44..3b3e6b9dc74 100644 --- a/source3/libsmb/clidfs.c +++ b/source3/libsmb/clidfs.c @@ -203,7 +203,9 @@ static NTSTATUS do_connect(TALLOC_CTX *ctx, /* If a password was not supplied then * try again with a null username. */ if (password[0] || !username[0] || + force_encrypt || smbXcli_conn_signing_mandatory(c->conn) || get_cmdline_auth_info_use_kerberos(auth_info) || + get_cmdline_auth_info_use_ccache(auth_info) || !NT_STATUS_IS_OK(status = cli_session_setup(c, "", "", 0, "", 0, -- 2.11.0 From 17019aa27f612f4ccc7131d40c54b26864fef444 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Mon, 14 Aug 2017 12:13:18 +0200 Subject: [PATCH 7/9] CVE-2017-12151: s3:libsmb: add cli_state_is_encryption_on() helper function This allows to check if the current cli_state uses encryption (either via unix extentions or via SMB3). BUG: https://bugzilla.samba.org/show_bug.cgi?id=12996 Signed-off-by: Stefan Metzmacher --- source3/libsmb/clientgen.c | 13 +++++++++++++ source3/libsmb/proto.h | 1 + 2 files changed, 14 insertions(+) diff --git a/source3/libsmb/clientgen.c b/source3/libsmb/clientgen.c index cfb3b162358..868ee59245b 100644 --- a/source3/libsmb/clientgen.c +++ b/source3/libsmb/clientgen.c @@ -339,6 +339,19 @@ uint16_t cli_getpid(struct cli_state *cli) return cli->smb1.pid; } +bool cli_state_is_encryption_on(struct cli_state *cli) +{ + if (smbXcli_conn_protocol(cli->conn) < PROTOCOL_SMB2_02) { + return smb1cli_conn_encryption_on(cli->conn); + } + + if (cli->smb2.tcon == NULL) { + return false; + } + + return smb2cli_tcon_is_encryption_on(cli->smb2.tcon); +} + bool cli_state_has_tcon(struct cli_state *cli) { uint16_t tid = cli_state_get_tid(cli); diff --git a/source3/libsmb/proto.h b/source3/libsmb/proto.h index dc9aa1720b2..e872e3106e7 100644 --- a/source3/libsmb/proto.h +++ b/source3/libsmb/proto.h @@ -174,6 +174,7 @@ const char *cli_state_remote_realm(struct cli_state *cli); uint16_t cli_state_get_vc_num(struct cli_state *cli); uint16_t cli_setpid(struct cli_state *cli, uint16_t pid); uint16_t cli_getpid(struct cli_state *cli); +bool cli_state_is_encryption_on(struct cli_state *cli); bool cli_state_has_tcon(struct cli_state *cli); uint16_t cli_state_get_tid(struct cli_state *cli); uint16_t cli_state_set_tid(struct cli_state *cli, uint16_t tid); -- 2.11.0 From 50f649e7d0b27bcd7eaab7d8223ef9ccd99782dc Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Sat, 17 Dec 2016 10:36:49 +0100 Subject: [PATCH 8/9] CVE-2017-12151: s3:libsmb: make use of cli_state_is_encryption_on() This will keep enforced encryption across dfs referrals. BUG: https://bugzilla.samba.org/show_bug.cgi?id=12996 Signed-off-by: Stefan Metzmacher --- source3/libsmb/clidfs.c | 4 ++-- source3/libsmb/libsmb_context.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/source3/libsmb/clidfs.c b/source3/libsmb/clidfs.c index 3b3e6b9dc74..074f8ed4dfd 100644 --- a/source3/libsmb/clidfs.c +++ b/source3/libsmb/clidfs.c @@ -954,7 +954,7 @@ NTSTATUS cli_resolve_path(TALLOC_CTX *ctx, "IPC$", dfs_auth_info, false, - smb1cli_conn_encryption_on(rootcli->conn), + cli_state_is_encryption_on(rootcli), smbXcli_conn_protocol(rootcli->conn), 0, 0x20, @@ -1012,7 +1012,7 @@ NTSTATUS cli_resolve_path(TALLOC_CTX *ctx, dfs_refs[count].share, dfs_auth_info, false, - smb1cli_conn_encryption_on(rootcli->conn), + cli_state_is_encryption_on(rootcli), smbXcli_conn_protocol(rootcli->conn), 0, 0x20, diff --git a/source3/libsmb/libsmb_context.c b/source3/libsmb/libsmb_context.c index 5e31dfbafb1..05133743c56 100644 --- a/source3/libsmb/libsmb_context.c +++ b/source3/libsmb/libsmb_context.c @@ -485,7 +485,7 @@ smbc_option_get(SMBCCTX *context, for (s = context->internal->servers; s; s = s->next) { num_servers++; - if (!smb1cli_conn_encryption_on(s->cli->conn)) { + if (!cli_state_is_encryption_on(s->cli)) { return (void *)false; } } -- 2.11.0 From bf85c3d4ed7a4f1a0be4e16faf5d9b562940d33d Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Fri, 8 Sep 2017 10:13:14 -0700 Subject: [PATCH 9/9] CVE-2017-12163: s3:smbd: Prevent client short SMB1 write from writing server memory to file. BUG: https://bugzilla.samba.org/show_bug.cgi?id=13020 Signed-off-by: Jeremy Allison Signed-off-by: Stefan Metzmacher --- source3/smbd/reply.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c index 3ba61a3b2bc..9896ff8c5fd 100644 --- a/source3/smbd/reply.c +++ b/source3/smbd/reply.c @@ -4463,6 +4463,9 @@ void reply_writebraw(struct smb_request *req) } /* Ensure we don't write bytes past the end of this packet. */ + /* + * This already protects us against CVE-2017-12163. + */ if (data + numtowrite > smb_base(req->inbuf) + smb_len(req->inbuf)) { reply_nterror(req, NT_STATUS_INVALID_PARAMETER); error_to_writebrawerr(req); @@ -4563,6 +4566,11 @@ void reply_writebraw(struct smb_request *req) exit_server_cleanly("secondary writebraw failed"); } + /* + * We are not vulnerable to CVE-2017-12163 + * here as we are guarenteed to have numtowrite + * bytes available - we just read from the client. + */ nwritten = write_file(req,fsp,buf+4,startpos+nwritten,numtowrite); if (nwritten == -1) { TALLOC_FREE(buf); @@ -4644,6 +4652,7 @@ void reply_writeunlock(struct smb_request *req) connection_struct *conn = req->conn; ssize_t nwritten = -1; size_t numtowrite; + size_t remaining; off_t startpos; const char *data; NTSTATUS status = NT_STATUS_OK; @@ -4676,6 +4685,17 @@ void reply_writeunlock(struct smb_request *req) startpos = IVAL_TO_SMB_OFF_T(req->vwv+2, 0); data = (const char *)req->buf + 3; + /* + * Ensure client isn't asking us to write more than + * they sent. CVE-2017-12163. + */ + remaining = smbreq_bufrem(req, data); + if (numtowrite > remaining) { + reply_nterror(req, NT_STATUS_INVALID_PARAMETER); + END_PROFILE(SMBwriteunlock); + return; + } + if (!fsp->print_file && numtowrite > 0) { init_strict_lock_struct(fsp, (uint64_t)req->smbpid, (uint64_t)startpos, (uint64_t)numtowrite, WRITE_LOCK, @@ -4757,6 +4777,7 @@ void reply_write(struct smb_request *req) { connection_struct *conn = req->conn; size_t numtowrite; + size_t remaining; ssize_t nwritten = -1; off_t startpos; const char *data; @@ -4797,6 +4818,17 @@ void reply_write(struct smb_request *req) startpos = IVAL_TO_SMB_OFF_T(req->vwv+2, 0); data = (const char *)req->buf + 3; + /* + * Ensure client isn't asking us to write more than + * they sent. CVE-2017-12163. + */ + remaining = smbreq_bufrem(req, data); + if (numtowrite > remaining) { + reply_nterror(req, NT_STATUS_INVALID_PARAMETER); + END_PROFILE(SMBwrite); + return; + } + if (!fsp->print_file) { init_strict_lock_struct(fsp, (uint64_t)req->smbpid, (uint64_t)startpos, (uint64_t)numtowrite, WRITE_LOCK, @@ -5023,6 +5055,9 @@ void reply_write_and_X(struct smb_request *req) goto out; } } else { + /* + * This already protects us against CVE-2017-12163. + */ if (smb_doff > smblen || smb_doff + numtowrite < numtowrite || smb_doff + numtowrite > smblen) { reply_nterror(req, NT_STATUS_INVALID_PARAMETER); @@ -5451,6 +5486,7 @@ void reply_writeclose(struct smb_request *req) { connection_struct *conn = req->conn; size_t numtowrite; + size_t remaining; ssize_t nwritten = -1; NTSTATUS close_status = NT_STATUS_OK; off_t startpos; @@ -5484,6 +5520,17 @@ void reply_writeclose(struct smb_request *req) mtime = convert_time_t_to_timespec(srv_make_unix_date3(req->vwv+4)); data = (const char *)req->buf + 1; + /* + * Ensure client isn't asking us to write more than + * they sent. CVE-2017-12163. + */ + remaining = smbreq_bufrem(req, data); + if (numtowrite > remaining) { + reply_nterror(req, NT_STATUS_INVALID_PARAMETER); + END_PROFILE(SMBwriteclose); + return; + } + if (fsp->print_file == NULL) { init_strict_lock_struct(fsp, (uint64_t)req->smbpid, (uint64_t)startpos, (uint64_t)numtowrite, WRITE_LOCK, @@ -6079,6 +6126,9 @@ void reply_printwrite(struct smb_request *req) numtowrite = SVAL(req->buf, 1); + /* + * This already protects us against CVE-2017-12163. + */ if (req->buflen < numtowrite + 3) { reply_nterror(req, NT_STATUS_INVALID_PARAMETER); END_PROFILE(SMBsplwr); -- 2.11.0