Which of the following is not a web application security vulnerability?Sensitive data exposureXML external entitiesNon-complianceInsecure deserialization

To determine which of the given options is not a web application security vulnerability, let's break down each term:

1. Sensitive Data Exposure: This refers to vulnerabilities that allow attackers to gain unauthorized access to sensitive data like passwords, credit card numbers, and personal information due to insufficient protection measures.

2. XML External Entities (XXE): This vulnerability involves processing XML input from untrusted sources, which can lead to the exposure of internal files and services.

3. Non-compliance: While non-compliance can lead to security issues, it itself is not classified as a specific security vulnerability. It refers to failing to adhere to compliance regulations and standards, such as GDPR or PCI-DSS.

4. Insecure Deserialization: This vulnerability occurs when untrusted data is used to create a data structure, potentially leading to code execution attacks.

Summary

From the analysis, Non-compliance is the option that is not a specific web application security vulnerability. It refers more to regulatory adherence rather than a direct security flaw. Thus, the answer is Non-compliance.