The first action that an IS auditor should take when finding a high-risk vulnerability in a public-facing web server used to process online customer payments is to identify compensating controls. Compensating controls are alternative or additional controls that provide reasonable assurance of mitigating the risk of exploiting the vulnerability. The IS auditor should assess the effectiveness of the compensating controls and determine whether they reduce the risk to an acceptable level. If not, the IS auditor should recommend remediation actions to address the vulnerability. Documenting the exception in an audit report is an important action, but it should not be the first action, as it does not address the urgency of the situation. Reviewing security incident reports is a useful action, but it should not be the first action, as it does not provide assurance of preventing future incidents. Notifying the audit committee is a necessary action, but it should not be the first action, as it does not involve taking any corrective measures. References:

CISA Review Manual, 27th Edition, pages 295-2961

CISA Review Questions, Answers and Explanations Database, Question ID: 260