From c129261c506c6b941630fd7f4bc72820eb272761 Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Fri, 1 Nov 2013 14:55:44 +1300 Subject: [PATCH 1/4] CVE-2013-4496:s3-samr: Block attempts to crack passwords via repeated password changes Bug: https://bugzilla.samba.org/show_bug.cgi?id=10245 Signed-off-by: Andrew Bartlett Signed-off-by: Stefan Metzmacher Signed-off-by: Jeremy Allison Reviewed-by: Stefan Metzmacher Reviewed-by: Jeremy Allison Reviewed-by: Andreas Schneider --- source3/rpc_server/samr/srv_samr_chgpasswd.c | 55 ++++++++++++++++ source3/rpc_server/samr/srv_samr_nt.c | 90 +++++++++++++++++++++----- 2 files changed, 129 insertions(+), 16 deletions(-) diff --git a/source3/rpc_server/samr/srv_samr_chgpasswd.c b/source3/rpc_server/samr/srv_samr_chgpasswd.c index db1f459..1c9c33a 100644 --- a/source3/rpc_server/samr/srv_samr_chgpasswd.c +++ b/source3/rpc_server/samr/srv_samr_chgpasswd.c @@ -1106,6 +1106,8 @@ NTSTATUS pass_oem_change(char *user, const char *rhost, struct samu *sampass = NULL; NTSTATUS nt_status; bool ret = false; + bool updated_badpw = false; + NTSTATUS update_login_attempts_status; if (!(sampass = samu_new(NULL))) { return NT_STATUS_NO_MEMORY; @@ -1121,6 +1123,13 @@ NTSTATUS pass_oem_change(char *user, const char *rhost, return NT_STATUS_NO_SUCH_USER; } + /* Quit if the account was locked out. */ + if (pdb_get_acct_ctrl(sampass) & ACB_AUTOLOCK) { + DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", user)); + TALLOC_FREE(sampass); + return NT_STATUS_ACCOUNT_LOCKED_OUT; + } + nt_status = check_oem_password(user, password_encrypted_with_lm_hash, old_lm_hash_encrypted, @@ -1129,6 +1138,52 @@ NTSTATUS pass_oem_change(char *user, const char *rhost, sampass, &new_passwd); + /* + * Notify passdb backend of login success/failure. If not + * NT_STATUS_OK the backend doesn't like the login + */ + update_login_attempts_status = pdb_update_login_attempts(sampass, + NT_STATUS_IS_OK(nt_status)); + + if (!NT_STATUS_IS_OK(nt_status)) { + bool increment_bad_pw_count = false; + + if (NT_STATUS_EQUAL(nt_status, NT_STATUS_WRONG_PASSWORD) && + (pdb_get_acct_ctrl(sampass) & ACB_NORMAL) && + NT_STATUS_IS_OK(update_login_attempts_status)) + { + increment_bad_pw_count = true; + } + + if (increment_bad_pw_count) { + pdb_increment_bad_password_count(sampass); + updated_badpw = true; + } else { + pdb_update_bad_password_count(sampass, + &updated_badpw); + } + } else { + + if ((pdb_get_acct_ctrl(sampass) & ACB_NORMAL) && + (pdb_get_bad_password_count(sampass) > 0)){ + pdb_set_bad_password_count(sampass, 0, PDB_CHANGED); + pdb_set_bad_password_time(sampass, 0, PDB_CHANGED); + updated_badpw = true; + } + } + + if (updated_badpw) { + NTSTATUS update_status; + become_root(); + update_status = pdb_update_sam_account(sampass); + unbecome_root(); + + if (!NT_STATUS_IS_OK(update_status)) { + DEBUG(1, ("Failed to modify entry: %s\n", + nt_errstr(update_status))); + } + } + if (!NT_STATUS_IS_OK(nt_status)) { TALLOC_FREE(sampass); return nt_status; diff --git a/source3/rpc_server/samr/srv_samr_nt.c b/source3/rpc_server/samr/srv_samr_nt.c index b366eda..98e8bea 100644 --- a/source3/rpc_server/samr/srv_samr_nt.c +++ b/source3/rpc_server/samr/srv_samr_nt.c @@ -1722,9 +1722,11 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, NTSTATUS status; bool ret = false; struct samr_user_info *uinfo; - struct samu *pwd; + struct samu *pwd = NULL; struct samr_Password new_lmPwdHash, new_ntPwdHash, checkHash; struct samr_Password lm_pwd, nt_pwd; + bool updated_badpw = false; + NTSTATUS update_login_attempts_status; uinfo = policy_handle_find(p, r->in.user_handle, SAMR_USER_ACCESS_SET_PASSWORD, NULL, @@ -1736,6 +1738,15 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, DEBUG(5,("_samr_ChangePasswordUser: sid:%s\n", sid_string_dbg(&uinfo->sid))); + /* basic sanity checking on parameters. Do this before any database ops */ + if (!r->in.lm_present || !r->in.nt_present || + !r->in.old_lm_crypted || !r->in.new_lm_crypted || + !r->in.old_nt_crypted || !r->in.new_nt_crypted) { + /* we should really handle a change with lm not + present */ + return NT_STATUS_INVALID_PARAMETER_MIX; + } + if (!(pwd = samu_new(NULL))) { return NT_STATUS_NO_MEMORY; } @@ -1749,6 +1760,14 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, return NT_STATUS_WRONG_PASSWORD; } + /* Quit if the account was locked out. */ + if (pdb_get_acct_ctrl(pwd) & ACB_AUTOLOCK) { + DEBUG(3, ("Account for user %s was locked out.\n", + pdb_get_username(pwd))); + status = NT_STATUS_ACCOUNT_LOCKED_OUT; + goto out; + } + { const uint8_t *lm_pass, *nt_pass; @@ -1757,29 +1776,19 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, if (!lm_pass || !nt_pass) { status = NT_STATUS_WRONG_PASSWORD; - goto out; + goto update_login; } memcpy(&lm_pwd.hash, lm_pass, sizeof(lm_pwd.hash)); memcpy(&nt_pwd.hash, nt_pass, sizeof(nt_pwd.hash)); } - /* basic sanity checking on parameters. Do this before any database ops */ - if (!r->in.lm_present || !r->in.nt_present || - !r->in.old_lm_crypted || !r->in.new_lm_crypted || - !r->in.old_nt_crypted || !r->in.new_nt_crypted) { - /* we should really handle a change with lm not - present */ - status = NT_STATUS_INVALID_PARAMETER_MIX; - goto out; - } - /* decrypt and check the new lm hash */ D_P16(lm_pwd.hash, r->in.new_lm_crypted->hash, new_lmPwdHash.hash); D_P16(new_lmPwdHash.hash, r->in.old_lm_crypted->hash, checkHash.hash); if (memcmp(checkHash.hash, lm_pwd.hash, 16) != 0) { status = NT_STATUS_WRONG_PASSWORD; - goto out; + goto update_login; } /* decrypt and check the new nt hash */ @@ -1787,7 +1796,7 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, D_P16(new_ntPwdHash.hash, r->in.old_nt_crypted->hash, checkHash.hash); if (memcmp(checkHash.hash, nt_pwd.hash, 16) != 0) { status = NT_STATUS_WRONG_PASSWORD; - goto out; + goto update_login; } /* The NT Cross is not required by Win2k3 R2, but if present @@ -1796,7 +1805,7 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, D_P16(lm_pwd.hash, r->in.nt_cross->hash, checkHash.hash); if (memcmp(checkHash.hash, new_ntPwdHash.hash, 16) != 0) { status = NT_STATUS_WRONG_PASSWORD; - goto out; + goto update_login; } } @@ -1806,7 +1815,7 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, D_P16(nt_pwd.hash, r->in.lm_cross->hash, checkHash.hash); if (memcmp(checkHash.hash, new_lmPwdHash.hash, 16) != 0) { status = NT_STATUS_WRONG_PASSWORD; - goto out; + goto update_login; } } @@ -1817,6 +1826,55 @@ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, } status = pdb_update_sam_account(pwd); + +update_login: + + /* + * Notify passdb backend of login success/failure. If not + * NT_STATUS_OK the backend doesn't like the login + */ + update_login_attempts_status = pdb_update_login_attempts(pwd, + NT_STATUS_IS_OK(status)); + + if (!NT_STATUS_IS_OK(status)) { + bool increment_bad_pw_count = false; + + if (NT_STATUS_EQUAL(status,NT_STATUS_WRONG_PASSWORD) && + (pdb_get_acct_ctrl(pwd) & ACB_NORMAL) && + NT_STATUS_IS_OK(update_login_attempts_status)) + { + increment_bad_pw_count = true; + } + + if (increment_bad_pw_count) { + pdb_increment_bad_password_count(pwd); + updated_badpw = true; + } else { + pdb_update_bad_password_count(pwd, + &updated_badpw); + } + } else { + + if ((pdb_get_acct_ctrl(pwd) & ACB_NORMAL) && + (pdb_get_bad_password_count(pwd) > 0)){ + pdb_set_bad_password_count(pwd, 0, PDB_CHANGED); + pdb_set_bad_password_time(pwd, 0, PDB_CHANGED); + updated_badpw = true; + } + } + + if (updated_badpw) { + NTSTATUS update_status; + become_root(); + update_status = pdb_update_sam_account(pwd); + unbecome_root(); + + if (!NT_STATUS_IS_OK(update_status)) { + DEBUG(1, ("Failed to modify entry: %s\n", + nt_errstr(update_status))); + } + } + out: TALLOC_FREE(pwd); -- 1.7.9.5 From fab5ee090e2e4765441b82e17a6cbb98523f6943 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Tue, 5 Nov 2013 14:04:20 +0100 Subject: [PATCH 2/4] CVE-2013-4496:s3:auth: fix memory leak in the ACCOUNT_LOCKED_OUT case. Bug: https://bugzilla.samba.org/show_bug.cgi?id=10245 Signed-off-by: Stefan Metzmacher Reviewed-by: Jeremy Allison Signed-off-by: Andrew Bartlett Reviewed-by: Andreas Schneider --- source3/auth/check_samsec.c | 1 + 1 file changed, 1 insertion(+) diff --git a/source3/auth/check_samsec.c b/source3/auth/check_samsec.c index 7ed8cc2..94f30b1 100644 --- a/source3/auth/check_samsec.c +++ b/source3/auth/check_samsec.c @@ -408,6 +408,7 @@ NTSTATUS check_sam_security(const DATA_BLOB *challenge, /* Quit if the account was locked out. */ if (pdb_get_acct_ctrl(sampass) & ACB_AUTOLOCK) { DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", username)); + TALLOC_FREE(sampass); return NT_STATUS_ACCOUNT_LOCKED_OUT; } -- 1.7.9.5 From bf3443c12f2a67481eb2e45ca41b906c438d06da Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Tue, 5 Nov 2013 16:16:46 +1300 Subject: [PATCH 3/4] CVE-2013-4496:samr: Remove ChangePasswordUser This old password change mechanism does not provide the plaintext to validate against password complexity, and it is not used by modern clients. The missing features in both implementations (by design) were: - the password complexity checks (no plaintext) - the minimum password length (no plaintext) Additionally, the source3 version did not check: - the minimum password age - pdb_get_pass_can_change() which checks the security descriptor for the 'user cannot change password' setting. - the password history - the output of the 'passwd program' if 'unix passwd sync = yes'. Finally, the mechanism was almost useless, as it was incorrectly only made available to administrative users with permission to reset the password. It is removed here so that it is not mistakenly reinstated in the future. Andrew Bartlett Bug: https://bugzilla.samba.org/show_bug.cgi?id=10245 Signed-off-by: Andrew Bartlett Reviewed-by: Andreas Schneider Reviewed-by: Stefan Metzmacher --- source3/rpc_server/samr/srv_samr_nt.c | 169 +------------------- source3/smbd/lanman.c | 254 ------------------------------- source4/rpc_server/samr/samr_password.c | 145 +----------------- source4/torture/rpc/samr.c | 6 + 4 files changed, 20 insertions(+), 554 deletions(-) diff --git a/source3/rpc_server/samr/srv_samr_nt.c b/source3/rpc_server/samr/srv_samr_nt.c index 98e8bea..99f03ec 100644 --- a/source3/rpc_server/samr/srv_samr_nt.c +++ b/source3/rpc_server/samr/srv_samr_nt.c @@ -1713,172 +1713,19 @@ NTSTATUS _samr_LookupNames(struct pipes_struct *p, } /**************************************************************** - _samr_ChangePasswordUser + _samr_ChangePasswordUser. + + So old it is just not worth implementing + because it does not supply a plaintext and so we can't do password + complexity checking and cannot update other services that use a + plaintext password via passwd chat/pam password change/ldap password + sync. ****************************************************************/ NTSTATUS _samr_ChangePasswordUser(struct pipes_struct *p, struct samr_ChangePasswordUser *r) { - NTSTATUS status; - bool ret = false; - struct samr_user_info *uinfo; - struct samu *pwd = NULL; - struct samr_Password new_lmPwdHash, new_ntPwdHash, checkHash; - struct samr_Password lm_pwd, nt_pwd; - bool updated_badpw = false; - NTSTATUS update_login_attempts_status; - - uinfo = policy_handle_find(p, r->in.user_handle, - SAMR_USER_ACCESS_SET_PASSWORD, NULL, - struct samr_user_info, &status); - if (!NT_STATUS_IS_OK(status)) { - return status; - } - - DEBUG(5,("_samr_ChangePasswordUser: sid:%s\n", - sid_string_dbg(&uinfo->sid))); - - /* basic sanity checking on parameters. Do this before any database ops */ - if (!r->in.lm_present || !r->in.nt_present || - !r->in.old_lm_crypted || !r->in.new_lm_crypted || - !r->in.old_nt_crypted || !r->in.new_nt_crypted) { - /* we should really handle a change with lm not - present */ - return NT_STATUS_INVALID_PARAMETER_MIX; - } - - if (!(pwd = samu_new(NULL))) { - return NT_STATUS_NO_MEMORY; - } - - become_root(); - ret = pdb_getsampwsid(pwd, &uinfo->sid); - unbecome_root(); - - if (!ret) { - TALLOC_FREE(pwd); - return NT_STATUS_WRONG_PASSWORD; - } - - /* Quit if the account was locked out. */ - if (pdb_get_acct_ctrl(pwd) & ACB_AUTOLOCK) { - DEBUG(3, ("Account for user %s was locked out.\n", - pdb_get_username(pwd))); - status = NT_STATUS_ACCOUNT_LOCKED_OUT; - goto out; - } - - { - const uint8_t *lm_pass, *nt_pass; - - lm_pass = pdb_get_lanman_passwd(pwd); - nt_pass = pdb_get_nt_passwd(pwd); - - if (!lm_pass || !nt_pass) { - status = NT_STATUS_WRONG_PASSWORD; - goto update_login; - } - - memcpy(&lm_pwd.hash, lm_pass, sizeof(lm_pwd.hash)); - memcpy(&nt_pwd.hash, nt_pass, sizeof(nt_pwd.hash)); - } - - /* decrypt and check the new lm hash */ - D_P16(lm_pwd.hash, r->in.new_lm_crypted->hash, new_lmPwdHash.hash); - D_P16(new_lmPwdHash.hash, r->in.old_lm_crypted->hash, checkHash.hash); - if (memcmp(checkHash.hash, lm_pwd.hash, 16) != 0) { - status = NT_STATUS_WRONG_PASSWORD; - goto update_login; - } - - /* decrypt and check the new nt hash */ - D_P16(nt_pwd.hash, r->in.new_nt_crypted->hash, new_ntPwdHash.hash); - D_P16(new_ntPwdHash.hash, r->in.old_nt_crypted->hash, checkHash.hash); - if (memcmp(checkHash.hash, nt_pwd.hash, 16) != 0) { - status = NT_STATUS_WRONG_PASSWORD; - goto update_login; - } - - /* The NT Cross is not required by Win2k3 R2, but if present - check the nt cross hash */ - if (r->in.cross1_present && r->in.nt_cross) { - D_P16(lm_pwd.hash, r->in.nt_cross->hash, checkHash.hash); - if (memcmp(checkHash.hash, new_ntPwdHash.hash, 16) != 0) { - status = NT_STATUS_WRONG_PASSWORD; - goto update_login; - } - } - - /* The LM Cross is not required by Win2k3 R2, but if present - check the lm cross hash */ - if (r->in.cross2_present && r->in.lm_cross) { - D_P16(nt_pwd.hash, r->in.lm_cross->hash, checkHash.hash); - if (memcmp(checkHash.hash, new_lmPwdHash.hash, 16) != 0) { - status = NT_STATUS_WRONG_PASSWORD; - goto update_login; - } - } - - if (!pdb_set_nt_passwd(pwd, new_ntPwdHash.hash, PDB_CHANGED) || - !pdb_set_lanman_passwd(pwd, new_lmPwdHash.hash, PDB_CHANGED)) { - status = NT_STATUS_ACCESS_DENIED; - goto out; - } - - status = pdb_update_sam_account(pwd); - -update_login: - - /* - * Notify passdb backend of login success/failure. If not - * NT_STATUS_OK the backend doesn't like the login - */ - update_login_attempts_status = pdb_update_login_attempts(pwd, - NT_STATUS_IS_OK(status)); - - if (!NT_STATUS_IS_OK(status)) { - bool increment_bad_pw_count = false; - - if (NT_STATUS_EQUAL(status,NT_STATUS_WRONG_PASSWORD) && - (pdb_get_acct_ctrl(pwd) & ACB_NORMAL) && - NT_STATUS_IS_OK(update_login_attempts_status)) - { - increment_bad_pw_count = true; - } - - if (increment_bad_pw_count) { - pdb_increment_bad_password_count(pwd); - updated_badpw = true; - } else { - pdb_update_bad_password_count(pwd, - &updated_badpw); - } - } else { - - if ((pdb_get_acct_ctrl(pwd) & ACB_NORMAL) && - (pdb_get_bad_password_count(pwd) > 0)){ - pdb_set_bad_password_count(pwd, 0, PDB_CHANGED); - pdb_set_bad_password_time(pwd, 0, PDB_CHANGED); - updated_badpw = true; - } - } - - if (updated_badpw) { - NTSTATUS update_status; - become_root(); - update_status = pdb_update_sam_account(pwd); - unbecome_root(); - - if (!NT_STATUS_IS_OK(update_status)) { - DEBUG(1, ("Failed to modify entry: %s\n", - nt_errstr(update_status))); - } - } - - out: - TALLOC_FREE(pwd); - - return status; + return NT_STATUS_NOT_IMPLEMENTED; } /******************************************************************* diff --git a/source3/smbd/lanman.c b/source3/smbd/lanman.c index e6b9530..1b734a7 100644 --- a/source3/smbd/lanman.c +++ b/source3/smbd/lanman.c @@ -2948,259 +2948,6 @@ static bool api_NetRemoteTOD(struct smbd_server_connection *sconn, } /**************************************************************************** - Set the user password. -*****************************************************************************/ - -static bool api_SetUserPassword(struct smbd_server_connection *sconn, - connection_struct *conn,uint64_t vuid, - char *param, int tpscnt, - char *data, int tdscnt, - int mdrcnt,int mprcnt, - char **rdata,char **rparam, - int *rdata_len,int *rparam_len) -{ - char *np = get_safe_str_ptr(param,tpscnt,param,2); - char *p = NULL; - fstring user; - fstring pass1,pass2; - TALLOC_CTX *mem_ctx = talloc_tos(); - NTSTATUS status, result; - struct rpc_pipe_client *cli = NULL; - struct policy_handle connect_handle, domain_handle, user_handle; - struct lsa_String domain_name; - struct dom_sid2 *domain_sid; - struct lsa_String names; - struct samr_Ids rids; - struct samr_Ids types; - struct samr_Password old_lm_hash; - struct samr_Password new_lm_hash; - int errcode = NERR_badpass; - uint32_t rid; - int encrypted; - int min_pwd_length; - struct dcerpc_binding_handle *b = NULL; - - /* Skip 2 strings. */ - p = skip_string(param,tpscnt,np); - p = skip_string(param,tpscnt,p); - - if (!np || !p) { - return False; - } - - /* Do we have a string ? */ - if (skip_string(param,tpscnt,p) == NULL) { - return False; - } - pull_ascii_fstring(user,p); - - p = skip_string(param,tpscnt,p); - if (!p) { - return False; - } - - memset(pass1,'\0',sizeof(pass1)); - memset(pass2,'\0',sizeof(pass2)); - /* - * We use 31 here not 32 as we're checking - * the last byte we want to access is safe. - */ - if (!is_offset_safe(param,tpscnt,p,31)) { - return False; - } - memcpy(pass1,p,16); - memcpy(pass2,p+16,16); - - encrypted = get_safe_SVAL(param,tpscnt,p+32,0,-1); - if (encrypted == -1) { - errcode = W_ERROR_V(WERR_INVALID_PARAM); - goto out; - } - - min_pwd_length = get_safe_SVAL(param,tpscnt,p+34,0,-1); - if (min_pwd_length == -1) { - errcode = W_ERROR_V(WERR_INVALID_PARAM); - goto out; - } - - *rparam_len = 4; - *rparam = smb_realloc_limit(*rparam,*rparam_len); - if (!*rparam) { - return False; - } - - *rdata_len = 0; - - DEBUG(3,("Set password for <%s> (encrypted: %d, min_pwd_length: %d)\n", - user, encrypted, min_pwd_length)); - - ZERO_STRUCT(connect_handle); - ZERO_STRUCT(domain_handle); - ZERO_STRUCT(user_handle); - - status = rpc_pipe_open_interface(mem_ctx, &ndr_table_samr.syntax_id, - conn->session_info, - conn->sconn->remote_address, - conn->sconn->msg_ctx, - &cli); - if (!NT_STATUS_IS_OK(status)) { - DEBUG(0,("api_SetUserPassword: could not connect to samr: %s\n", - nt_errstr(status))); - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - - b = cli->binding_handle; - - status = dcerpc_samr_Connect2(b, mem_ctx, - lp_netbios_name(), - SAMR_ACCESS_CONNECT_TO_SERVER | - SAMR_ACCESS_ENUM_DOMAINS | - SAMR_ACCESS_LOOKUP_DOMAIN, - &connect_handle, - &result); - if (!NT_STATUS_IS_OK(status)) { - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - if (!NT_STATUS_IS_OK(result)) { - errcode = W_ERROR_V(ntstatus_to_werror(result)); - goto out; - } - - init_lsa_String(&domain_name, get_global_sam_name()); - - status = dcerpc_samr_LookupDomain(b, mem_ctx, - &connect_handle, - &domain_name, - &domain_sid, - &result); - if (!NT_STATUS_IS_OK(status)) { - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - if (!NT_STATUS_IS_OK(result)) { - errcode = W_ERROR_V(ntstatus_to_werror(result)); - goto out; - } - - status = dcerpc_samr_OpenDomain(b, mem_ctx, - &connect_handle, - SAMR_DOMAIN_ACCESS_OPEN_ACCOUNT, - domain_sid, - &domain_handle, - &result); - if (!NT_STATUS_IS_OK(status)) { - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - if (!NT_STATUS_IS_OK(result)) { - errcode = W_ERROR_V(ntstatus_to_werror(result)); - goto out; - } - - init_lsa_String(&names, user); - - status = dcerpc_samr_LookupNames(b, mem_ctx, - &domain_handle, - 1, - &names, - &rids, - &types, - &result); - if (!NT_STATUS_IS_OK(status)) { - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - if (!NT_STATUS_IS_OK(result)) { - errcode = W_ERROR_V(ntstatus_to_werror(result)); - goto out; - } - - if (rids.count != 1) { - errcode = W_ERROR_V(WERR_NO_SUCH_USER); - goto out; - } - if (rids.count != types.count) { - errcode = W_ERROR_V(WERR_INVALID_PARAM); - goto out; - } - if (types.ids[0] != SID_NAME_USER) { - errcode = W_ERROR_V(WERR_INVALID_PARAM); - goto out; - } - - rid = rids.ids[0]; - - status = dcerpc_samr_OpenUser(b, mem_ctx, - &domain_handle, - SAMR_USER_ACCESS_CHANGE_PASSWORD, - rid, - &user_handle, - &result); - if (!NT_STATUS_IS_OK(status)) { - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - if (!NT_STATUS_IS_OK(result)) { - errcode = W_ERROR_V(ntstatus_to_werror(result)); - goto out; - } - - if (encrypted == 0) { - E_deshash(pass1, old_lm_hash.hash); - E_deshash(pass2, new_lm_hash.hash); - } else { - ZERO_STRUCT(old_lm_hash); - ZERO_STRUCT(new_lm_hash); - memcpy(old_lm_hash.hash, pass1, MIN(strlen(pass1), 16)); - memcpy(new_lm_hash.hash, pass2, MIN(strlen(pass2), 16)); - } - - status = dcerpc_samr_ChangePasswordUser(b, mem_ctx, - &user_handle, - true, /* lm_present */ - &old_lm_hash, - &new_lm_hash, - false, /* nt_present */ - NULL, /* old_nt_crypted */ - NULL, /* new_nt_crypted */ - false, /* cross1_present */ - NULL, /* nt_cross */ - false, /* cross2_present */ - NULL, /* lm_cross */ - &result); - if (!NT_STATUS_IS_OK(status)) { - errcode = W_ERROR_V(ntstatus_to_werror(status)); - goto out; - } - if (!NT_STATUS_IS_OK(result)) { - errcode = W_ERROR_V(ntstatus_to_werror(result)); - goto out; - } - - errcode = NERR_Success; - out: - - if (b && is_valid_policy_hnd(&user_handle)) { - dcerpc_samr_Close(b, mem_ctx, &user_handle, &result); - } - if (b && is_valid_policy_hnd(&domain_handle)) { - dcerpc_samr_Close(b, mem_ctx, &domain_handle, &result); - } - if (b && is_valid_policy_hnd(&connect_handle)) { - dcerpc_samr_Close(b, mem_ctx, &connect_handle, &result); - } - - memset((char *)pass1,'\0',sizeof(fstring)); - memset((char *)pass2,'\0',sizeof(fstring)); - - SSVAL(*rparam,0,errcode); - SSVAL(*rparam,2,0); /* converter word */ - return(True); -} - -/**************************************************************************** Set the user password (SamOEM version - gets plaintext). ****************************************************************************/ @@ -5797,7 +5544,6 @@ static const struct { {"NetServerEnum2", RAP_NetServerEnum2, api_RNetServerEnum2}, /* anon OK */ {"NetServerEnum3", RAP_NetServerEnum3, api_RNetServerEnum3}, /* anon OK */ {"WAccessGetUserPerms",RAP_WAccessGetUserPerms,api_WAccessGetUserPerms}, - {"SetUserPassword", RAP_WUserPasswordSet2, api_SetUserPassword}, {"WWkstaUserLogon", RAP_WWkstaUserLogon, api_WWkstaUserLogon}, {"PrintJobInfo", RAP_WPrintJobSetInfo, api_PrintJobInfo}, {"WPrintDriverEnum", RAP_WPrintDriverEnum, api_WPrintDriverEnum}, diff --git a/source4/rpc_server/samr/samr_password.c b/source4/rpc_server/samr/samr_password.c index 2d9c48a..9d6c921 100644 --- a/source4/rpc_server/samr/samr_password.c +++ b/source4/rpc_server/samr/samr_password.c @@ -33,150 +33,17 @@ /* samr_ChangePasswordUser + + So old it is just not worth implementing + because it does not supply a plaintext and so we can't do password + complexity checking and cannot update all the other password hashes. + */ NTSTATUS dcesrv_samr_ChangePasswordUser(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx, struct samr_ChangePasswordUser *r) { - struct dcesrv_handle *h; - struct samr_account_state *a_state; - struct ldb_context *sam_ctx; - struct ldb_message **res; - int ret; - struct samr_Password new_lmPwdHash, new_ntPwdHash, checkHash; - struct samr_Password *lm_pwd, *nt_pwd; - NTSTATUS status = NT_STATUS_OK; - const char * const attrs[] = { "dBCSPwd", "unicodePwd" , NULL }; - - DCESRV_PULL_HANDLE(h, r->in.user_handle, SAMR_HANDLE_USER); - - a_state = h->data; - - /* basic sanity checking on parameters. Do this before any database ops */ - if (!r->in.lm_present || !r->in.nt_present || - !r->in.old_lm_crypted || !r->in.new_lm_crypted || - !r->in.old_nt_crypted || !r->in.new_nt_crypted) { - /* we should really handle a change with lm not - present */ - return NT_STATUS_INVALID_PARAMETER_MIX; - } - - /* Connect to a SAMDB with system privileges for fetching the old pw - * hashes. */ - sam_ctx = samdb_connect(mem_ctx, dce_call->event_ctx, - dce_call->conn->dce_ctx->lp_ctx, - system_session(dce_call->conn->dce_ctx->lp_ctx), 0); - if (sam_ctx == NULL) { - return NT_STATUS_INVALID_SYSTEM_SERVICE; - } - - /* fetch the old hashes */ - ret = gendb_search_dn(sam_ctx, mem_ctx, - a_state->account_dn, &res, attrs); - if (ret != 1) { - return NT_STATUS_WRONG_PASSWORD; - } - - status = samdb_result_passwords(mem_ctx, - dce_call->conn->dce_ctx->lp_ctx, - res[0], &lm_pwd, &nt_pwd); - if (!NT_STATUS_IS_OK(status) || !nt_pwd) { - return NT_STATUS_WRONG_PASSWORD; - } - - /* decrypt and check the new lm hash */ - if (lm_pwd) { - D_P16(lm_pwd->hash, r->in.new_lm_crypted->hash, new_lmPwdHash.hash); - D_P16(new_lmPwdHash.hash, r->in.old_lm_crypted->hash, checkHash.hash); - } - - /* decrypt and check the new nt hash */ - D_P16(nt_pwd->hash, r->in.new_nt_crypted->hash, new_ntPwdHash.hash); - D_P16(new_ntPwdHash.hash, r->in.old_nt_crypted->hash, checkHash.hash); - - /* The NT Cross is not required by Win2k3 R2, but if present - check the nt cross hash */ - if (r->in.cross1_present && r->in.nt_cross && lm_pwd) { - D_P16(lm_pwd->hash, r->in.nt_cross->hash, checkHash.hash); - } - - /* The LM Cross is not required by Win2k3 R2, but if present - check the lm cross hash */ - if (r->in.cross2_present && r->in.lm_cross && lm_pwd) { - D_P16(nt_pwd->hash, r->in.lm_cross->hash, checkHash.hash); - } - - /* Start a SAM with user privileges for the password change */ - sam_ctx = samdb_connect(mem_ctx, dce_call->event_ctx, - dce_call->conn->dce_ctx->lp_ctx, - dce_call->conn->auth_state.session_info, 0); - if (sam_ctx == NULL) { - return NT_STATUS_INVALID_SYSTEM_SERVICE; - } - - /* Start transaction */ - ret = ldb_transaction_start(sam_ctx); - if (ret != LDB_SUCCESS) { - DEBUG(1, ("Failed to start transaction: %s\n", ldb_errstring(sam_ctx))); - return NT_STATUS_TRANSACTION_ABORTED; - } - - /* Performs the password modification. We pass the old hashes read out - * from the database since they were already checked against the user- - * provided ones. */ - status = samdb_set_password(sam_ctx, mem_ctx, - a_state->account_dn, - a_state->domain_state->domain_dn, - NULL, &new_lmPwdHash, &new_ntPwdHash, - lm_pwd, nt_pwd, /* this is a user password change */ - NULL, - NULL); - if (!NT_STATUS_IS_OK(status)) { - ldb_transaction_cancel(sam_ctx); - return status; - } - - /* decrypt and check the new lm hash */ - if (lm_pwd) { - if (memcmp(checkHash.hash, lm_pwd, 16) != 0) { - ldb_transaction_cancel(sam_ctx); - return NT_STATUS_WRONG_PASSWORD; - } - } - - if (memcmp(checkHash.hash, nt_pwd, 16) != 0) { - ldb_transaction_cancel(sam_ctx); - return NT_STATUS_WRONG_PASSWORD; - } - - /* The NT Cross is not required by Win2k3 R2, but if present - check the nt cross hash */ - if (r->in.cross1_present && r->in.nt_cross && lm_pwd) { - if (memcmp(checkHash.hash, new_ntPwdHash.hash, 16) != 0) { - ldb_transaction_cancel(sam_ctx); - return NT_STATUS_WRONG_PASSWORD; - } - } - - /* The LM Cross is not required by Win2k3 R2, but if present - check the lm cross hash */ - if (r->in.cross2_present && r->in.lm_cross && lm_pwd) { - if (memcmp(checkHash.hash, new_lmPwdHash.hash, 16) != 0) { - ldb_transaction_cancel(sam_ctx); - return NT_STATUS_WRONG_PASSWORD; - } - } - - /* And this confirms it in a transaction commit */ - ret = ldb_transaction_commit(sam_ctx); - if (ret != LDB_SUCCESS) { - DEBUG(1,("Failed to commit transaction to change password on %s: %s\n", - ldb_dn_get_linearized(a_state->account_dn), - ldb_errstring(sam_ctx))); - return NT_STATUS_TRANSACTION_ABORTED; - } - - return NT_STATUS_OK; + return NT_STATUS_NOT_IMPLEMENTED; } /* diff --git a/source4/torture/rpc/samr.c b/source4/torture/rpc/samr.c index a0a5f1a..cdfa2b8 100644 --- a/source4/torture/rpc/samr.c +++ b/source4/torture/rpc/samr.c @@ -1759,6 +1759,12 @@ static bool test_ChangePasswordUser(struct dcerpc_binding_handle *b, torture_comment(tctx, "(%s:%s) old_password[%s] new_password[%s] status[%s]\n", __location__, __FUNCTION__, oldpass, newpass, nt_errstr(r.out.result)); + + /* Do not proceed if this call has been removed */ + if (NT_STATUS_EQUAL(r.out.result, NT_STATUS_NOT_IMPLEMENTED)) { + return true; + } + if (!NT_STATUS_EQUAL(r.out.result, NT_STATUS_PASSWORD_RESTRICTION)) { torture_assert_ntstatus_equal(tctx, r.out.result, NT_STATUS_WRONG_PASSWORD, "ChangePasswordUser failed: expected NT_STATUS_WRONG_PASSWORD because we broke the LM hash"); -- 1.7.9.5 From b0281ad59d3ba8b32787ce112fb4a83d935c60d1 Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Thu, 28 Nov 2013 06:50:01 +1300 Subject: [PATCH 4/4] CVE-2013-4496:Revert remainder of ce895609b04380bfc41e4f8fddc84bd2f9324340 Part of this was removed when ChangePasswordUser was unimplemented, but remove the remainder of this flawed commit. Fully check the password first, as extract_pw_from_buffer() already does a partial check of the password because it needs a correct old password to correctly decrypt the length. Andrew Bartlett Bug: https://bugzilla.samba.org/show_bug.cgi?id=10245 Signed-off-by: Andrew Bartlett Reviewed-by: Andreas Schneider Reviewed-by: Stefan Metzmacher --- source4/rpc_server/samr/samr_password.c | 69 ++++++++++++++++--------------- 1 file changed, 35 insertions(+), 34 deletions(-) diff --git a/source4/rpc_server/samr/samr_password.c b/source4/rpc_server/samr/samr_password.c index 9d6c921..685a8e7 100644 --- a/source4/rpc_server/samr/samr_password.c +++ b/source4/rpc_server/samr/samr_password.c @@ -142,6 +142,9 @@ NTSTATUS dcesrv_samr_OemChangePasswordUser2(struct dcesrv_call_state *dce_call, E_deshash(new_pass, new_lm_hash); E_old_pw_hash(new_lm_hash, lm_pwd->hash, lm_verifier.hash); + if (memcmp(lm_verifier.hash, r->in.hash->hash, 16) != 0) { + return NT_STATUS_WRONG_PASSWORD; + } /* Connect to a SAMDB with user privileges for the password change */ sam_ctx = samdb_connect(mem_ctx, dce_call->event_ctx, @@ -173,11 +176,6 @@ NTSTATUS dcesrv_samr_OemChangePasswordUser2(struct dcesrv_call_state *dce_call, return status; } - if (memcmp(lm_verifier.hash, r->in.hash->hash, 16) != 0) { - ldb_transaction_cancel(sam_ctx); - return NT_STATUS_WRONG_PASSWORD; - } - /* And this confirms it in a transaction commit */ ret = ldb_transaction_commit(sam_ctx); if (ret != LDB_SUCCESS) { @@ -267,33 +265,8 @@ NTSTATUS dcesrv_samr_ChangePasswordUser3(struct dcesrv_call_state *dce_call, goto failed; } - /* Connect to a SAMDB with user privileges for the password change */ - sam_ctx = samdb_connect(mem_ctx, dce_call->event_ctx, - dce_call->conn->dce_ctx->lp_ctx, - dce_call->conn->auth_state.session_info, 0); - if (sam_ctx == NULL) { - return NT_STATUS_INVALID_SYSTEM_SERVICE; - } - - ret = ldb_transaction_start(sam_ctx); - if (ret != LDB_SUCCESS) { - DEBUG(1, ("Failed to start transaction: %s\n", ldb_errstring(sam_ctx))); - return NT_STATUS_TRANSACTION_ABORTED; - } - - /* Performs the password modification. We pass the old hashes read out - * from the database since they were already checked against the user- - * provided ones. */ - status = samdb_set_password(sam_ctx, mem_ctx, - user_dn, NULL, - &new_password, - NULL, NULL, - lm_pwd, nt_pwd, /* this is a user password change */ - &reason, - &dominfo); - - if (!NT_STATUS_IS_OK(status)) { - ldb_transaction_cancel(sam_ctx); + if (r->in.nt_verifier == NULL) { + status = NT_STATUS_WRONG_PASSWORD; goto failed; } @@ -302,7 +275,6 @@ NTSTATUS dcesrv_samr_ChangePasswordUser3(struct dcesrv_call_state *dce_call, E_old_pw_hash(new_nt_hash, nt_pwd->hash, nt_verifier.hash); if (memcmp(nt_verifier.hash, r->in.nt_verifier->hash, 16) != 0) { - ldb_transaction_cancel(sam_ctx); status = NT_STATUS_WRONG_PASSWORD; goto failed; } @@ -322,13 +294,42 @@ NTSTATUS dcesrv_samr_ChangePasswordUser3(struct dcesrv_call_state *dce_call, E_deshash(new_pass, new_lm_hash); E_old_pw_hash(new_nt_hash, lm_pwd->hash, lm_verifier.hash); if (memcmp(lm_verifier.hash, r->in.lm_verifier->hash, 16) != 0) { - ldb_transaction_cancel(sam_ctx); status = NT_STATUS_WRONG_PASSWORD; goto failed; } } } + /* Connect to a SAMDB with user privileges for the password change */ + sam_ctx = samdb_connect(mem_ctx, dce_call->event_ctx, + dce_call->conn->dce_ctx->lp_ctx, + dce_call->conn->auth_state.session_info, 0); + if (sam_ctx == NULL) { + return NT_STATUS_INVALID_SYSTEM_SERVICE; + } + + ret = ldb_transaction_start(sam_ctx); + if (ret != LDB_SUCCESS) { + DEBUG(1, ("Failed to start transaction: %s\n", ldb_errstring(sam_ctx))); + return NT_STATUS_TRANSACTION_ABORTED; + } + + /* Performs the password modification. We pass the old hashes read out + * from the database since they were already checked against the user- + * provided ones. */ + status = samdb_set_password(sam_ctx, mem_ctx, + user_dn, NULL, + &new_password, + NULL, NULL, + lm_pwd, nt_pwd, /* this is a user password change */ + &reason, + &dominfo); + + if (!NT_STATUS_IS_OK(status)) { + ldb_transaction_cancel(sam_ctx); + goto failed; + } + /* And this confirms it in a transaction commit */ ret = ldb_transaction_commit(sam_ctx); if (ret != LDB_SUCCESS) { -- 1.7.9.5