Microsoft Identity Web is a library which contains a set of reusable classes used in conjunction with ASP.NET Core for integrating with the Microsoft identity platform (formerly Azure AD v2.0 endpoint) and AAD B2C. This vulnerability affects confidential client applications, including daemons, web apps, and web APIs. Under specific circumstances, sensitive information such as client secrets or certificate details may be exposed in the service logs of these applications. Service logs are intended to be handled securely. Service logs generated at the information level or credential descriptions containing local file paths with passwords, Base64 encoded values, or Client secret. Additionally, logs of services using Base64 encoded certificates or certificate paths with password credential descriptions are also affected if the certificates are invalid or expired, regardless of the log level. Note that these credentials are not usable due to their invalid or expired status. To mitigate this vulnerability, update to Microsoft.Identity.Web 3.8.2 or Microsoft.Identity.Abstractions 9.0.0.
Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.
While logging all information may be helpful during development stages, it is important that logging levels be set appropriately before a product ships so that sensitive user data and system information are not accidentally exposed to potential attackers. Different log files may be produced and stored for: