Rule Definition
APIs rely on clients to perform data filtering. Since APIs are used as data sources, sometimes developers try to implement them in a generic way without thinking about the sensitivity of the exposed data.
When you rely on the front-end for filtering sensitive data there is an underlying API that is returning all the data, which may be more than needed. This helps the attacker to understand the schema or intercept data that they are not intended to know.
Remediation
Never rely on the client side to filter sensitive data.
Reference
https://github.com/OWASP/API-Security/blob/master/2019/en/src/0xa3-excessive-data-exposure.md
Related Technologies
Technical Criterion
Secure Coding - API Abuse
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