A05 Security Misconfiguration - OWASP Top 10:2021
This OWASP category warns against misconfigurations that create vulnerabilities. Learn how to prevent them and prevent common attack scenarios.
Overview
Moving up from #6 in the previous edition, 90% of applications were tested for some form of misconfiguration, with an average incidence rate of 4.%, and over 208k occurrences of a Common Weakness Enumeration (CWE) in this risk category. With more shifts into highly configurable software, it's not surprising to see this category move up.
Description
The application might be vulnerable if the application is missing appropriate security hardening across any part of the application stack or improperly configured permissions on cloud services. Unnecessary features are enabled or installed, default accounts and their passwords are still enabled and unchanged, error handling reveals stack traces or other overly informative error messages to users, and many more potential vulnerabilities.
How to Prevent ?
Secure installation processes should be implemented, including a repeatable hardening process, a minimal platform without unnecessary features, regular review and update of security configurations, segmented application architecture, sending security directives to clients, and an automated process to verify the effectiveness of the configurations and settings.
Example Attack Scenarios:
Scenario #1: Default Accounts and Sample Applications: The application server comes with sample applications not removed from the production server. These sample applications have known security flaws attackers use to compromise the server. Suppose one of these applications is the admin console, and default accounts weren't changed. In that case, the attacker logs in with default passwords and takes over.
Scenario #2: Directory Listing: Directory listing is not disabled on the server. An attacker discovers they can simply list directories. The attacker finds and downloads the compiled Java classes, which they decompile and reverse engineer to view the code. The attacker then finds a severe access control flaw in the application.
Scenario #3: Error Messages: The application server's configuration allows detailed error messages, e.g., stack traces, to be returned to users. This potentially exposes sensitive information or underlying flaws such as component versions that are known to be vulnerable.
Scenario #4: Cloud Service Permissions: A cloud service provider (CSP) has default sharing permissions open to the Internet by other CSP users. This allows sensitive data stored within cloud storage to be accessed.