NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability

Security Vulnerability

Released: Jan 9, 2024

Last updated: Apr 16, 2024

Assigning CNA
Microsoft
CVE.org link
CVE-2024-0057
Impact
Elevation of Privilege
Max Severity
Important
Weakness
CVSS Source
Microsoft
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:P/RL:O/RC:C

Please see Common Vulnerability Scoring System for more information on the definition of these metrics.

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed
No
Exploited
No
Exploitability assessment
Exploitation Less Likely

FAQ

How could an attacker exploit this vulnerability?

An attacker could exploit this by creating a specially crafted X.509 certificate that intentionally introduce or intentionally induces a chain building failure.

What kind of security feature could be bypassed by successfully exploiting this vulnerability?

A security feature bypass vulnerability exists when Microsoft .NET Framework-based applications use X.509 chain building APIs but do not completely validate the X.509 certificate due to a logic flaw. An attacker could present an arbitrary untrusted certificate with malformed signatures, triggering a bug in the framework. The framework will correctly report that X.509 chain building failed, but it will return an incorrect reason code for the failure. Applications which utilize this reason code to make their own chain building trust decisions may inadvertently treat this scenario as a successful chain build. This could allow an adversary to subvert the app's typical authentication logic.

Is there are reason for such a high CVSS score?

Yes, the CVSS scoring guide recommends using a reasonable worst-case implementation scenario when scoring vulnerabilities in software libraries. Vulnerabilites in .NET Framework and similar products are scored with this advice in mind. The score for your implmentation this product may not be as severe, however we recommend installing the update as soon as possible in an abundance of caution.

Please see the CVSS user guide for more information.

Acknowledgements

  • Vishal Mishra and Anita Gaud with Microsoft's Azure DevSec Variant Hunt Team and Stav Nir from Microsoft
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

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