CompTIA PenTest+ (PT0-003) PT0-003 — Question 331

A penetration tester conducts a web application assessment and receives the following Set-Cookie upon logging in: Set-Cookie auth=UGVudGVzdFVzZXI6OTE1MzYK Upon analysis, the penetration tester determines this is a Base64-encoded string, which when decoded reads: Pentestuser:91536 - The penetration tester logs out, logs back in, and sees the decoded string now reads: Pentestuser:91944 - Which of the following attacks will the penetration tester most likely conduct based on this information?