API8:2023 Security Misconfiguration - OWASP API Security Top 10

Overview

API8:2023 Security Misconfiguration is one of the top 10 API security risks identified by OWASP (Open Web Application Security Project). This security risk occurs when an API is not properly configured, leaving it vulnerable to unauthorized access or compromise. Attackers can exploit security misconfigurations to gain access to sensitive user data and system details, potentially leading to a full server compromise. This article provides an overview of API8:2023 Security Misconfiguration, example attack scenarios, and preventive measures to mitigate this risk.

Description

API8:2023 Security Misconfiguration is a common security risk in APIs. Attackers target APIs with unpatched flaws, insecure default configurations, or unprotected files and directories. Security misconfigurations can occur at any level of the API stack, from the network level to the application level. This exposes sensitive user data and system details, opening the door for unauthorized access or full server compromise. It is crucial for developers and organizations to be aware of this risk and take preventive measures to secure their APIs.

How to Prevent ?

To prevent API8:2023 Security Misconfiguration, it is important to follow secure configuration practices throughout the API lifecycle. This includes a repeatable hardening process to deploy a properly locked down environment, regular reviews and updates of configurations across the entire API stack, and continuous assessment of configuration effectiveness. Additionally, it is recommended to ensure encrypted communication channels (TLS) for all API communications, restrict API access to specific HTTP verbs, implement Cross-Origin Resource Sharing (CORS) policies and applicable security headers for browser-based clients, and define and enforce API response payload schemas. It is also important to reference secure coding practices and guidelines provided by OWASP and external sources.

Example Attack Scenarios:

• Scenario #1:  In this scenario, an API back-end server has an access log written by a third-party logging utility with support for placeholder expansion and Java Naming and Directory Interface (JNDI) lookups. A bad actor issues an API request that contains a malicious payload in the X-Api-Version header. Due to the insecure default configuration of the logging utility, the payload gets executed, leading to unauthorized access or compromise of the server.

• Scenario #2:  In this scenario, a social network website's API does not include the Cache-Control HTTP response header in its responses. This leads to private conversations being cached by web browsers, which can be retrieved by malicious actors from the browser cache files. This exposes sensitive user information and compromises the privacy of the users.