Advisory Details

September 9th, 2025

Microsoft .NET IsTypeAuthorized Deserialization of Untrusted Data Denial-of-Service Vulnerability

ZDI-25-892
ZDI-CAN-24739

CVE ID
CVSS SCORE 7.5, AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS .NET
VULNERABILITY DETAILS

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Microsoft .NET. Interaction with the .NET framework is required to exploit this vulnerability but attack vectors may vary depending on the implementation.

The specific flaw exists within the implementations of the IsTypeAuthorized method on .NET workflow classes. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.

ADDITIONAL DETAILS

Fixed in versions SP2016, SP2019, and SPSE Sept 2024 PU


DISCLOSURE TIMELINE
  • 2024-07-12 - Vulnerability reported to vendor
  • 2025-09-09 - Coordinated public release of advisory
  • 2025-09-09 - Advisory Updated
CREDIT Piotr Bazydlo (@chudypb) of Trend Micro Zero Day Initiative
BACK TO ADVISORIES