Problem: Here is an easy way to step around SharePoint 2013's input field validation for a drop down list. Any list contains a drop-down list (configured to only allowed to chose values from the dropdown list), using Internet Explorer (IE) dev tools and amending the DOM, when posting the form, the change value is inserted into the list.
- Open IE go to the list to add a new list item (the list must have a drop down field column), hit Fn+F12 to open the IE Dev toolbar.
- In the "DOM Explorer" tab select the "Select element" icon (top left).
- Click on the drop down control i.e. "Primary/Secondary" input control as shown below.
- Edit the DOM value for the item selected to some crazy text and save the form.
- Open the item in view mode and you will see the crazy data as shown below circled in red in the bottom picture.