From ee105156fa151ebfd34b8febc2928e144b3b7b0e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?G=C3=BCnther=20Deschner?= Date: Sat, 26 Sep 2015 01:29:10 +0200 Subject: [PATCH 01/15] CVE-2016-2111: s3:rpc_server/netlogon: always go through netr_creds_server_step_check() The ensures we apply the "server schannel = yes" restrictions. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11749 Pair-Programmed-With: Stefan Metzmacher Signed-off-by: Guenther Deschner Signed-off-by: Stefan Metzmacher --- source3/rpc_server/netlogon/srv_netlog_nt.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) --- source3/rpc_server/netlogon/srv_netlog_nt.c +++ source3/rpc_server/netlogon/srv_netlog_nt.c @@ -1508,6 +1508,7 @@ static NTSTATUS _netr_LogonSamLogon_base case NetlogonNetworkTransitiveInformation: { const char *wksname = nt_workstation; + const char *workgroup = lp_workgroup(); status = make_auth_context_fixed(talloc_tos(), &auth_context, logon->network->challenge); @@ -1532,6 +1533,14 @@ static NTSTATUS _netr_LogonSamLogon_base logon->network->nt.length)) { status = NT_STATUS_NO_MEMORY; } + + if (NT_STATUS_IS_OK(status)) { + status = NTLMv2_RESPONSE_verify_netlogon_creds( + user_info->client.account_name, + user_info->client.domain_name, + user_info->password.response.nt, + creds, workgroup); + } break; } case NetlogonInteractiveInformation: @@ -1636,6 +1645,14 @@ static NTSTATUS _netr_LogonSamLogon_base r->out.validation->sam3); break; case 6: + /* Only allow this if the pipe is protected. */ + if (p->auth.auth_level < DCERPC_AUTH_LEVEL_PRIVACY) { + DEBUG(0,("netr_Validation6: client %s not using privacy for netlogon\n", + get_remote_machine_name())); + status = NT_STATUS_INVALID_PARAMETER; + break; + } + status = serverinfo_to_SamInfo6(server_info, pipe_session_key, 16, r->out.validation->sam6); break; @@ -2271,11 +2288,13 @@ NTSTATUS _netr_GetForestTrustInformation /* TODO: check server name */ - status = schannel_check_creds_state(p->mem_ctx, lp_private_dir(), - r->in.computer_name, - r->in.credential, - r->out.return_authenticator, - &creds); + become_root(); + status = netr_creds_server_step_check(p, p->mem_ctx, + r->in.computer_name, + r->in.credential, + r->out.return_authenticator, + &creds); + unbecome_root(); if (!NT_STATUS_IS_OK(status)) { return status; } @@ -2371,11 +2390,13 @@ NTSTATUS _netr_ServerGetTrustInfo(struct /* TODO: check server name */ - status = schannel_check_creds_state(p->mem_ctx, lp_private_dir(), - r->in.computer_name, - r->in.credential, - r->out.return_authenticator, - &creds); + become_root(); + status = netr_creds_server_step_check(p, p->mem_ctx, + r->in.computer_name, + r->in.credential, + r->out.return_authenticator, + &creds); + unbecome_root(); if (!NT_STATUS_IS_OK(status)) { return status; } --- source4/torture/rpc/samba3rpc.c +++ source4/torture/rpc/samba3rpc.c @@ -1122,8 +1122,8 @@ static bool schan(struct torture_context generate_random_buffer(chal.data, chal.length); names_blob = NTLMv2_generate_names_blob( mem_ctx, - cli_credentials_get_workstation(user_creds), - cli_credentials_get_domain(user_creds)); + cli_credentials_get_workstation(wks_creds), + cli_credentials_get_domain(wks_creds)); status = cli_credentials_get_ntlm_response( user_creds, mem_ctx, &flags, chal, names_blob, &lm_resp, &nt_resp, NULL, NULL); --- libcli/auth/proto.h +++ libcli/auth/proto.h @@ -139,6 +139,11 @@ bool SMBNTLMv2encrypt(TALLOC_CTX *mem_ct const DATA_BLOB *names_blob, DATA_BLOB *lm_response, DATA_BLOB *nt_response, DATA_BLOB *lm_session_key, DATA_BLOB *user_session_key) ; +NTSTATUS NTLMv2_RESPONSE_verify_netlogon_creds(const char *account_name, + const char *account_domain, + const DATA_BLOB response, + const struct netlogon_creds_CredentialState *creds, + const char *workgroup); /*********************************************************** encode a password buffer with a unicode password. The buffer --- libcli/auth/smbencrypt.c +++ libcli/auth/smbencrypt.c @@ -26,7 +26,7 @@ #include "../libcli/auth/msrpc_parse.h" #include "../lib/crypto/crypto.h" #include "../libcli/auth/libcli_auth.h" -#include "../librpc/gen_ndr/ntlmssp.h" +#include "../librpc/gen_ndr/ndr_ntlmssp.h" void SMBencrypt_hash(const uint8_t lm_hash[16], const uint8_t *c8, uint8_t p24[24]) { @@ -522,6 +522,146 @@ bool SMBNTLMv2encrypt(TALLOC_CTX *mem_ct lm_response, nt_response, lm_session_key, user_session_key); } +NTSTATUS NTLMv2_RESPONSE_verify_netlogon_creds(const char *account_name, + const char *account_domain, + const DATA_BLOB response, + const struct netlogon_creds_CredentialState *creds, + const char *workgroup) +{ + TALLOC_CTX *frame = NULL; + /* RespType + HiRespType */ + static const char *magic = "\x01\x01"; + int cmp; + struct NTLMv2_RESPONSE v2_resp; + enum ndr_err_code err; + const struct AV_PAIR *av_nb_cn = NULL; + const struct AV_PAIR *av_nb_dn = NULL; + + if (response.length < 48) { + /* + * NTLMv2_RESPONSE has at least 48 bytes. + */ + return NT_STATUS_OK; + } + + cmp = memcmp(response.data + 16, magic, 2); + if (cmp != 0) { + /* + * It doesn't look like a valid NTLMv2_RESPONSE + */ + return NT_STATUS_OK; + } + + frame = talloc_stackframe(); + + err = ndr_pull_struct_blob(&response, frame, &v2_resp, + (ndr_pull_flags_fn_t)ndr_pull_NTLMv2_RESPONSE); + if (!NDR_ERR_CODE_IS_SUCCESS(err)) { + NTSTATUS status; + status = ndr_map_error2ntstatus(err); + DEBUG(2,("Failed to parse NTLMv2_RESPONSE " + "length %u - %s - %s\n", + (unsigned)response.length, + ndr_map_error2string(err), + nt_errstr(status))); + dump_data(2, response.data, response.length); + TALLOC_FREE(frame); + return status; + } + + if (DEBUGLVL(10)) { + NDR_PRINT_DEBUG(NTLMv2_RESPONSE, &v2_resp); + } + + /* + * Make sure the netbios computer name in the + * NTLMv2_RESPONSE matches the computer name + * in the secure channel credentials for workstation + * trusts. + * + * And the netbios domain name matches our + * workgroup. + * + * This prevents workstations from requesting + * the session key of NTLMSSP sessions of clients + * to other hosts. + */ + if (creds->secure_channel_type == SEC_CHAN_WKSTA) { + av_nb_cn = ndr_ntlmssp_find_av(&v2_resp.Challenge.AvPairs, + MsvAvNbComputerName); + av_nb_dn = ndr_ntlmssp_find_av(&v2_resp.Challenge.AvPairs, + MsvAvNbDomainName); + } + + if (av_nb_cn != NULL) { + const char *v = NULL; + char *a = NULL; + size_t len; + + v = av_nb_cn->Value.AvNbComputerName; + + a = talloc_strdup(frame, creds->account_name); + if (a == NULL) { + TALLOC_FREE(frame); + return NT_STATUS_NO_MEMORY; + } + len = strlen(a); + if (len > 0 && a[len - 1] == '$') { + a[len - 1] = '\0'; + } + +#ifdef SAMBA4_INTERNAL_HEIMDAL /* smbtorture4 for make test */ + cmp = strcasecmp_m(a, v); +#else /* smbd */ + cmp = StrCaseCmp(a, v); +#endif + if (cmp != 0) { + DEBUG(2,("%s: NTLMv2_RESPONSE with " + "NbComputerName[%s] rejected " + "for user[%s\\%s] " + "against SEC_CHAN_WKSTA[%s/%s] " + "in workgroup[%s]\n", + __func__, v, + account_domain, + account_name, + creds->computer_name, + creds->account_name, + workgroup)); + TALLOC_FREE(frame); + return NT_STATUS_LOGON_FAILURE; + } + } + if (av_nb_dn != NULL) { + const char *v = NULL; + + v = av_nb_dn->Value.AvNbDomainName; + +#ifdef SAMBA4_INTERNAL_HEIMDAL /* smbtorture4 for make test */ + cmp = strcasecmp_m(workgroup, v); +#else /* smbd */ + cmp = StrCaseCmp(workgroup, v); +#endif + if (cmp != 0) { + DEBUG(2,("%s: NTLMv2_RESPONSE with " + "NbDomainName[%s] rejected " + "for user[%s\\%s] " + "against SEC_CHAN_WKSTA[%s/%s] " + "in workgroup[%s]\n", + __func__, v, + account_domain, + account_name, + creds->computer_name, + creds->account_name, + workgroup)); + TALLOC_FREE(frame); + return NT_STATUS_LOGON_FAILURE; + } + } + + TALLOC_FREE(frame); + return NT_STATUS_OK; +} + /*********************************************************** encode a password buffer with a unicode password. The buffer is filled with random data to make it harder to attack. --- libcli/auth/wscript_build +++ libcli/auth/wscript_build @@ -19,7 +19,7 @@ bld.SAMBA_SUBSYSTEM('MSRPC_PARSE', bld.SAMBA_SUBSYSTEM('LIBCLI_AUTH', source='credentials.c session.c smbencrypt.c smbdes.c', - public_deps='MSRPC_PARSE', + public_deps='MSRPC_PARSE NDR_NTLMSSP', public_headers='credentials.h:domain_credentials.h' ) --- source3/Makefile.in +++ source3/Makefile.in @@ -783,6 +783,7 @@ GROUPDB_OBJ = groupdb/mapping.o groupdb/ PROFILE_OBJ = profile/profile.o PROFILES_OBJ = utils/profiles.o \ $(LIBSMB_ERR_OBJ) \ + $(LIBNDR_NTLMSSP_OBJ) \ $(PARAM_OBJ) \ $(LIB_OBJ) $(LIB_DUMMY_OBJ) \ $(POPT_LIB_OBJ) \ @@ -995,10 +996,10 @@ SWAT_OBJ = $(SWAT_OBJ1) $(PARAM_OBJ) $(P STATUS_OBJ = utils/status.o utils/status_profile.o \ $(LOCKING_OBJ) $(PARAM_OBJ) \ $(PROFILE_OBJ) $(LIB_NONSMBD_OBJ) $(POPT_LIB_OBJ) \ - $(LIBSMB_ERR_OBJ) $(FNAME_UTIL_OBJ) + $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) $(FNAME_UTIL_OBJ) SMBCONTROL_OBJ = utils/smbcontrol.o $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) \ - $(LIBSMB_ERR_OBJ) $(POPT_LIB_OBJ) $(PRINTBASE_OBJ) + $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) $(POPT_LIB_OBJ) $(PRINTBASE_OBJ) SMBTREE_OBJ = utils/smbtree.o $(PARAM_OBJ) \ $(PROFILE_OBJ) $(LIB_NONSMBD_OBJ) $(LIBSMB_OBJ) \ @@ -1012,11 +1013,11 @@ SMBTREE_OBJ = utils/smbtree.o $(PARAM_OB TESTPARM_OBJ = utils/testparm.o \ $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) $(POPT_LIB_OBJ) \ - $(LIBSMB_ERR_OBJ) + $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) SMBTA_UTIL_OBJ = utils/smbta-util.o $(PARAM_OBJ) $(POPT_LIB_OBJ) \ $(LIB_NONSMBD_OBJ) \ - $(LIBSMB_ERR_OBJ) $(FNAME_UTIL_OBJ) + $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) $(FNAME_UTIL_OBJ) TEST_LP_LOAD_OBJ = param/test_lp_load.o \ $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) \ @@ -1146,6 +1147,7 @@ SMBCONFTORT_OBJ = $(SMBCONFTORT_OBJ0) \ $(LIB_NONSMBD_OBJ) \ $(PARAM_OBJ) \ $(LIBSMB_ERR_OBJ) \ + $(LIBNDR_NTLMSSP_OBJ) \ $(POPT_LIB_OBJ) PTHREADPOOLTEST_OBJ = lib/pthreadpool/pthreadpool.o \ @@ -1229,7 +1231,7 @@ CUPS_OBJ = client/smbspool.o $(PARAM_OBJ $(LIBNDR_GEN_OBJ0) NMBLOOKUP_OBJ = utils/nmblookup.o $(PARAM_OBJ) $(LIBNMB_OBJ) \ - $(LIB_NONSMBD_OBJ) $(POPT_LIB_OBJ) $(LIBSMB_ERR_OBJ) + $(LIB_NONSMBD_OBJ) $(POPT_LIB_OBJ) $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) SMBTORTURE_OBJ1 = torture/torture.o torture/nbio.o torture/scanner.o torture/utable.o \ torture/denytest.o torture/mangle_test.o \ @@ -1253,6 +1255,7 @@ MASKTEST_OBJ = torture/masktest.o $(PARA $(LIBNDR_GEN_OBJ0) MSGTEST_OBJ = torture/msgtest.o $(PARAM_OBJ) $(LIBSMB_ERR_OBJ) \ + $(LIBNDR_NTLMSSP_OBJ) \ $(LIB_NONSMBD_OBJ) \ $(LIBNDR_GEN_OBJ0) @@ -1269,7 +1272,7 @@ PDBTEST_OBJ = torture/pdbtest.o $(PARAM_ VFSTEST_OBJ = torture/cmd_vfs.o torture/vfstest.o $(SMBD_OBJ_BASE) $(READLINE_OBJ) -SMBICONV_OBJ = $(PARAM_OBJ) torture/smbiconv.o $(LIB_NONSMBD_OBJ) $(POPT_LIB_OBJ) $(LIBSMB_ERR_OBJ) +SMBICONV_OBJ = $(PARAM_OBJ) torture/smbiconv.o $(LIB_NONSMBD_OBJ) $(POPT_LIB_OBJ) $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) LOG2PCAP_OBJ = utils/log2pcaphex.o @@ -1297,17 +1300,17 @@ SMBCQUOTAS_OBJ = utils/smbcquotas.o $(LI EVTLOGADM_OBJ0 = utils/eventlogadm.o EVTLOGADM_OBJ = $(EVTLOGADM_OBJ0) $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) \ - $(LIBSMB_ERR_OBJ) $(LIB_EVENTLOG_OBJ) \ + $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) $(LIB_EVENTLOG_OBJ) \ librpc/gen_ndr/ndr_eventlog.o \ librpc/gen_ndr/ndr_lsa.o SHARESEC_OBJ0 = utils/sharesec.o SHARESEC_OBJ = $(SHARESEC_OBJ0) $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) \ - $(LIBSMB_ERR_OBJ) \ + $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) \ $(POPT_LIB_OBJ) TALLOCTORT_OBJ = @tallocdir@/testsuite.o @tallocdir@/testsuite_main.o \ - $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) $(LIBSMB_ERR_OBJ) + $(PARAM_OBJ) $(LIB_NONSMBD_OBJ) $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) REPLACETORT_OBJ = @libreplacedir@/test/testsuite.o \ @libreplacedir@/test/getifaddrs.o \ @@ -1323,7 +1326,7 @@ SMBFILTER_OBJ = utils/smbfilter.o $(PARA $(LIBNDR_GEN_OBJ0) WINBIND_WINS_NSS_OBJ = ../nsswitch/wins.o $(PARAM_OBJ) \ - $(LIB_NONSMBD_OBJ) $(LIBSMB_ERR_OBJ) $(LIBNMB_OBJ) + $(LIB_NONSMBD_OBJ) $(LIBSMB_ERR_OBJ) $(LIBNDR_NTLMSSP_OBJ) $(LIBNMB_OBJ) PAM_SMBPASS_OBJ_0 = pam_smbpass/pam_smb_auth.o pam_smbpass/pam_smb_passwd.o \ pam_smbpass/pam_smb_acct.o pam_smbpass/support.o ../lib/util/asn1.o @@ -1531,12 +1534,14 @@ RPC_OPEN_TCP_OBJ = torture/rpc_open_tcp. DBWRAP_TOOL_OBJ = utils/dbwrap_tool.o \ $(PARAM_OBJ) \ $(LIB_NONSMBD_OBJ) \ - $(LIBSMB_ERR_OBJ) + $(LIBSMB_ERR_OBJ) \ + $(LIBNDR_NTLMSSP_OBJ) DBWRAP_TORTURE_OBJ = utils/dbwrap_torture.o \ $(PARAM_OBJ) \ $(LIB_NONSMBD_OBJ) \ $(LIBSMB_ERR_OBJ) \ + $(LIBNDR_NTLMSSP_OBJ) \ $(POPT_LIB_OBJ) SPLIT_TOKENS_OBJ = utils/split_tokens.o \ --- source4/torture/raw/samba3misc.c +++ source4/torture/raw/samba3misc.c @@ -340,6 +340,7 @@ bool torture_samba3_badpath(struct tortu bool ret = true; TALLOC_CTX *mem_ctx; bool nt_status_support; + bool client_ntlmv2_auth; if (!(mem_ctx = talloc_init("torture_samba3_badpath"))) { d_printf("talloc_init failed\n"); @@ -347,20 +348,17 @@ bool torture_samba3_badpath(struct tortu } nt_status_support = lpcfg_nt_status_support(torture->lp_ctx); + client_ntlmv2_auth = lpcfg_client_ntlmv2_auth(torture->lp_ctx); - if (!lpcfg_set_cmdline(torture->lp_ctx, "nt status support", "yes")) { - printf("Could not set 'nt status support = yes'\n"); - goto fail; - } + torture_assert_goto(torture, lpcfg_set_cmdline(torture->lp_ctx, "nt status support", "yes"), ret, fail, "Could not set 'nt status support = yes'\n"); + torture_assert_goto(torture, lpcfg_set_cmdline(torture->lp_ctx, "client ntlmv2 auth", "yes"), ret, fail, "Could not set 'client ntlmv2 auth = yes'\n"); if (!torture_open_connection(&cli_nt, torture, 0)) { goto fail; } - if (!lpcfg_set_cmdline(torture->lp_ctx, "nt status support", "no")) { - printf("Could not set 'nt status support = yes'\n"); - goto fail; - } + torture_assert_goto(torture, lpcfg_set_cmdline(torture->lp_ctx, "nt status support", "no"), ret, fail, "Could not set 'nt status support = no'\n"); + torture_assert_goto(torture, lpcfg_set_cmdline(torture->lp_ctx, "client ntlmv2 auth", "no"), ret, fail, "Could not set 'client ntlmv2 auth = no'\n"); if (!torture_open_connection(&cli_dos, torture, 1)) { goto fail; @@ -373,6 +371,12 @@ bool torture_samba3_badpath(struct tortu } smbcli_deltree(cli_nt->tree, dirname); + torture_assert_goto(torture, lpcfg_set_cmdline(torture->lp_ctx, "nt status support", + nt_status_support ? "yes":"no"), + ret, fail, "Could not set 'nt status support' back to where it was\n"); + torture_assert_goto(torture, lpcfg_set_cmdline(torture->lp_ctx, "client ntlmv2 auth", + client_ntlmv2_auth ? "yes":"no"), + ret, fail, "Could not set 'client ntlmv2 auth' back to where it was\n"); status = smbcli_mkdir(cli_nt->tree, dirname); if (!NT_STATUS_IS_OK(status)) { --- source4/torture/basic/base.c +++ source4/torture/basic/base.c @@ -1476,6 +1476,7 @@ static bool torture_chkpath_test(struct static bool torture_samba3_errorpaths(struct torture_context *tctx) { bool nt_status_support; + bool client_ntlmv2_auth; struct smbcli_state *cli_nt = NULL, *cli_dos = NULL; bool result = false; int fnum; @@ -1485,18 +1486,27 @@ static bool torture_samba3_errorpaths(st NTSTATUS status; nt_status_support = lpcfg_nt_status_support(tctx->lp_ctx); + client_ntlmv2_auth = lpcfg_client_ntlmv2_auth(tctx->lp_ctx); if (!lpcfg_set_cmdline(tctx->lp_ctx, "nt status support", "yes")) { torture_comment(tctx, "Could not set 'nt status support = yes'\n"); goto fail; } + if (!lpcfg_set_cmdline(tctx->lp_ctx, "client ntlmv2 auth", "yes")) { + torture_result(tctx, TORTURE_FAIL, "Could not set 'client ntlmv2 auth = yes'\n"); + goto fail; + } if (!torture_open_connection(&cli_nt, tctx, 0)) { goto fail; } if (!lpcfg_set_cmdline(tctx->lp_ctx, "nt status support", "no")) { - torture_comment(tctx, "Could not set 'nt status support = yes'\n"); + torture_result(tctx, TORTURE_FAIL, "Could not set 'nt status support = no'\n"); + goto fail; + } + if (!lpcfg_set_cmdline(tctx->lp_ctx, "client ntlmv2 auth", "no")) { + torture_result(tctx, TORTURE_FAIL, "Could not set 'client ntlmv2 auth = no'\n"); goto fail; } @@ -1506,7 +1516,12 @@ static bool torture_samba3_errorpaths(st if (!lpcfg_set_cmdline(tctx->lp_ctx, "nt status support", nt_status_support ? "yes":"no")) { - torture_comment(tctx, "Could not reset 'nt status support = yes'"); + torture_result(tctx, TORTURE_FAIL, "Could not reset 'nt status support'"); + goto fail; + } + if (!lpcfg_set_cmdline(tctx->lp_ctx, "client ntlmv2 auth", + client_ntlmv2_auth ? "yes":"no")) { + torture_result(tctx, TORTURE_FAIL, "Could not reset 'client ntlmv2 auth'"); goto fail; } --- source3/libsmb/cliconnect.c +++ source3/libsmb/cliconnect.c @@ -2077,6 +2077,17 @@ NTSTATUS cli_session_setup(struct cli_st NTSTATUS status; /* otherwise do a NT1 style session setup */ + if (lp_client_ntlmv2_auth() && lp_client_use_spnego()) { + /* + * Don't send an NTLMv2 response without NTLMSSP + * if we want to use spnego support + */ + DEBUG(1, ("Server does not support EXTENDED_SECURITY " + " but 'client use spnego = yes" + " and 'client ntlmv2 auth = yes'\n")); + return NT_STATUS_ACCESS_DENIED; + } + status = cli_session_setup_nt1(cli, user, pass, passlen, ntpass, ntpasslen, workgroup); if (!NT_STATUS_IS_OK(status)) { --- docs-xml/smbdotconf/protocol/clientusespnego.xml +++ docs-xml/smbdotconf/protocol/clientusespnego.xml @@ -9,6 +9,11 @@ supporting servers (including WindowsXP, Windows2000 and Samba 3.0) to agree upon an authentication mechanism. This enables Kerberos authentication in particular. + + When is also set to + yes extended security (SPNEGO) is required + in order to use NTLMv2 only within NTLMSSP. This behavior was + introduced with the patches for CVE-2016-2111. yes --- docs-xml/smbdotconf/security/clientntlmv2auth.xml +++ docs-xml/smbdotconf/security/clientntlmv2auth.xml @@ -28,6 +28,11 @@ NTLMv2 by default, and some sites (particularly those following 'best practice' security polices) only allow NTLMv2 responses, and not the weaker LM or NTLM. + + When is also set to + yes extended security (SPNEGO) is required + in order to use NTLMv2 only within NTLMSSP. This behavior was + introduced with the patches for CVE-2016-2111. yes --- /dev/null +++ docs-xml/smbdotconf/security/rawntlmv2auth.xml @@ -0,0 +1,19 @@ + + + This parameter determines whether or not smbd + 8 will allow SMB1 clients without + extended security (without SPNEGO) to use NTLMv2 authentication. + + If this option, lanman auth + and ntlm auth are all disabled, + then only clients with SPNEGO support will be permitted. + That means NTLMv2 is only supported within NTLMSSP. + + +lanman auth +ntlm auth +no + --- source3/include/proto.h +++ source3/include/proto.h @@ -1489,6 +1489,7 @@ bool lp_map_untrusted_to_domain(void); int lp_restrict_anonymous(void); bool lp_lanman_auth(void); bool lp_ntlm_auth(void); +bool lp_raw_ntlmv2_auth(void); bool lp_client_plaintext_auth(void); bool lp_client_lanman_auth(void); bool lp_client_ntlmv2_auth(void); --- source3/param/loadparm.c +++ source3/param/loadparm.c @@ -336,6 +336,7 @@ struct global { bool bAllowTrustedDomains; bool bLanmanAuth; bool bNTLMAuth; + bool bRawNTLMv2Auth; bool bUseSpnego; bool bClientLanManAuth; bool bClientNTLMv2Auth; @@ -1383,6 +1384,15 @@ static struct parm_struct parm_table[] = .flags = FLAG_ADVANCED, }, { + .label = "raw NTLMv2 auth", + .type = P_BOOL, + .p_class = P_GLOBAL, + .ptr = &Globals.bRawNTLMv2Auth, + .special = NULL, + .enum_list = NULL, + .flags = FLAG_ADVANCED, + }, + { .label = "client NTLMv2 auth", .type = P_BOOL, .p_class = P_GLOBAL, @@ -5337,6 +5347,7 @@ static void init_globals(bool reinit_glo Globals.bClientPlaintextAuth = False; /* Do NOT use a plaintext password even if is requested by the server */ Globals.bLanmanAuth = False; /* Do NOT use the LanMan hash, even if it is supplied */ Globals.bNTLMAuth = True; /* Do use NTLMv1 if it is supplied by the client (otherwise NTLMv2) */ + Globals.bRawNTLMv2Auth = false; /* Allow NTLMv2 without NTLMSSP */ Globals.bClientNTLMv2Auth = True; /* Client should always use use NTLMv2, as we can't tell that the server supports it, but most modern servers do */ /* Note, that we will also use NTLM2 session security (which is different), if it is available */ @@ -5819,6 +5830,7 @@ FN_GLOBAL_BOOL(lp_map_untrusted_to_domai FN_GLOBAL_INTEGER(lp_restrict_anonymous, &Globals.restrict_anonymous) FN_GLOBAL_BOOL(lp_lanman_auth, &Globals.bLanmanAuth) FN_GLOBAL_BOOL(lp_ntlm_auth, &Globals.bNTLMAuth) +FN_GLOBAL_BOOL(lp_raw_ntlmv2_auth, &Globals.bRawNTLMv2Auth) FN_GLOBAL_BOOL(lp_client_plaintext_auth, &Globals.bClientPlaintextAuth) FN_GLOBAL_BOOL(lp_client_lanman_auth, &Globals.bClientLanManAuth) FN_GLOBAL_BOOL(lp_client_ntlmv2_auth, &Globals.bClientNTLMv2Auth) --- source3/auth/auth_util.c +++ source3/auth/auth_util.c @@ -30,6 +30,7 @@ #include "../lib/util/util_pw.h" #include "lib/winbind_util.h" #include "passdb.h" +#include "../lib/tsocket/tsocket.h" #undef DBGC_CLASS #define DBGC_CLASS DBGC_AUTH @@ -367,6 +368,19 @@ NTSTATUS make_user_info_for_reply_enc(st const char *client_domain, DATA_BLOB lm_resp, DATA_BLOB nt_resp) { + bool allow_raw = lp_raw_ntlmv2_auth(); + + if (!allow_raw && nt_resp.length >= 48) { + /* + * NTLMv2_RESPONSE has at least 48 bytes + * and should only be supported via NTLMSSP. + */ + DEBUG(2,("Rejecting raw NTLMv2 authentication with " + "user [%s\\%s]\n", + client_domain, smb_name)); + return NT_STATUS_INVALID_PARAMETER; + } + return make_user_info_map(user_info, smb_name, client_domain, get_remote_machine_name(), --- selftest/target/Samba3.pm +++ selftest/target/Samba3.pm @@ -127,6 +127,7 @@ sub setup_dc($$) domain master = yes domain logons = yes lanman auth = yes + raw NTLMv2 auth = yes "; my $vars = $self->provision($path, @@ -230,6 +231,7 @@ sub setup_secserver($$$) my $secserver_options = " security = server password server = $s3dcvars->{SERVER_IP} + client ntlmv2 auth = no "; my $ret = $self->provision($prefix,