Newton is concerned that attackers could be exploiting a vulnerability in software to gain access to resources that the user normally would be restricted from accessing. What type of attack is he worried about?

Privilege escalation

Explanation:

Privilege escalation is defined as the kind of network intrusion performed by a programmer who takes advantage of programming errors through three succeeding systems that trust each other. In case of Newton's worry, he's concerned of attackers that might exploit vulnerability in software hence gaining access to resources that users are restricted from accessing. The three succeeding systems are clearly defined here as software, resources, and end-users hence this type of attack called privilege escalation