CVE-2019-16929: Improper Authentication in Auth0.AuthenticationApi
Summary
CVE-2019-16929: Improper Authentication in Auth0.AuthenticationApi. Affects Auth0.AuthenticationApi versions >= 5.8.0, < 6.5.4. Fixed in 6.5.4. How to fix ↓
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Background
Auth0.AuthenticationApi is a NuGet package that provides authentication functionality for applications. It is used to handle authentication and authorization processes, including user authentication, token validation, and access control. The package is widely used in various applications to ensure secure user authentication. However, an improper authentication vulnerability has been identified in versions prior to 6.5.4 of the package.
Vulnerability Detail
The vulnerability, identified as CVE-2019-16929, is an Incorrect Access Control issue in Auth0.AuthenticationApi. The package's IdentityTokenValidator can be mistakenly used to validate untrusted ID tokens, leading to unauthorized access. This vulnerability can potentially allow attackers to bypass authentication mechanisms and gain unauthorized access to sensitive resources or perform unauthorized actions within the application. The severity of this vulnerability is rated as HIGH with a CVSS score of 7.5.
How To Fix
Latest published version: 7.49.0 as of 23 Oct 2026
Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
6.5.4
This is the first release that contains the fix.
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Workaround
There is no specific workaround mentioned for this vulnerability. The recommended solution is to upgrade to the fixed version of the package.
Conclusion
In conclusion, the Auth0.AuthenticationApi package prior to version 6.5.4 is vulnerable to an Incorrect Access Control issue. This vulnerability can lead to unauthorized access and potential misuse of sensitive resources. It is crucial for developers to upgrade to the fixed version of the package to mitigate this vulnerability. For further support on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for Auth0.AuthenticationApi →
FAQ
Auth0.AuthenticationApi is a NuGet package that provides authentication functionality for applications, including user authentication, token validation, and access control.
This vulnerability can allow attackers to bypass authentication mechanisms and gain unauthorized access to sensitive resources or perform unauthorized actions within the application.
The severity of this vulnerability is rated as HIGH with a CVSS score of 7.5.
To fix this vulnerability, it is recommended to upgrade to version 6.5.4 or later of the Auth0.AuthenticationApi package.
There is no specific workaround mentioned for this vulnerability. The recommended solution is to upgrade to the fixed version of the package.
