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.  It also has quite difficult semantics to handle regarding
password lockout.

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

Change-Id: If2edd3183c177e5ff37c9511b0d0ad0dd9038c66
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-on: https://gerrit.samba.org/37

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 a7700c6bd6..48cfc7e12d 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 f7f77534ee..63c2ad7cae 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,
-					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 2d9c48abd7..9d6c9212f4 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 6b6ffc30f1..c0d8039331 100644
--- a/source4/torture/rpc/samr.c
+++ b/source4/torture/rpc/samr.c
@@ -1758,6 +1758,12 @@ 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)) {
+		torture_skip(tctx, "ValidatePassword not supported by server\n");
+	}
+
 	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");