Affected: WSO2 API Manager, WSO2 Identity Server, WSO2 Identity Server as Key Manager

The error handling implementation fails to properly sanitize or validate user-supplied input within URL parameters under specific conditions. This allows end-users to manipulate the error messages that are displayed by the application.

By exploiting this vulnerability, malicious actors can inject arbitrary content into error messages. This enables them to perform social engineering attacks, such as phishing or credential theft, by replacing legitimate error messages with malicious content, misleading users into compromising sensitive information or taking harmful actions.