GlideAjax call returning "null" for customer users

[Prem5]

Hi all,

I have an On-Change client script that makes a Glide Ajax call and returns a value. The script include which is being called has a function with simple script making a Glide record on Sold Product(sn_install_base_sold_product).

The script is working fine when logged in as an admin, but when logged in as a customer it is returning "null". I figured it may be an issue with the Query rules as we have OOTB CSM query rules on Sold product table. I created a new query rule to provide read access for a particular customer role, but still the script is returning "null". Any leads or help with the troubleshooting of this issue is appreciated.

Attaching my client script and script include code for reference.
Client Script:

function onChange(control, oldValue, newValue, isLoading) {
    if (isLoading || newValue == '') {
        return;
    }
    ajaxCallserial();
}

function ajaxCallserial() {
    var serialNumber = g_form.getValue('product_key');
    var numCheck = new GlideAjax('global.ClaimProductUtilsAjax');
    numCheck.addParam('sysparm_name', 'validateSerialNumber');
    numCheck.addParam('sysparm_serialNumber', serialNumber);
    numCheck.getXML(handleResponse);

    function handleResponse(response) {
        var answer = response.responseXML.documentElement.getAttribute("answer");
		alert(answer);
        if (answer == 'false') {
            g_form.setValue('response_variable', "false");
        } else{
            g_form.setValue('response_variable', "true");
		}
    }
}

 Script Include:

 validateSerialNumber: function() {
        var serialnumber = this.getParameter('sysparm_serialNumber');
		
        var checkNum = new GlideRecord('sn_install_base_sold_product');
        checkNum.addQuery('u_sold_product_serial_number', serialnumber);
        checkNum.query();
        if (checkNum.hasNext()) {
            return true;
        } else return false;

    },

[Ashwini Jadhao]

@Prem5 ,

In your script Include use GlideRecordSecure() instead of GlideRecord().

validateSerialNumber: function() {
        var serialnumber = this.getParameter('sysparm_serialNumber');
		
        var checkNum = new GlideRecordSecure('sn_install_base_sold_product');
        checkNum.addQuery('u_sold_product_serial_number', serialnumber);
        checkNum.query();
        if (checkNum.hasNext()) {
            return true;
        } else return false;

    },

Please mark my answer helpful and correct if it works for you.