Microsoft Security Advisory CVE-2024-43499 | .NET Denial of Service Vulnerability #73
Description
Microsoft Security Advisory CVE-2024-43499 | .NET Denial of Service Vulnerability
Executive Summary
Microsoft is releasing this security advisory to provide information about a vulnerability in PowerShell 7.5. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.
The NrbfDecoder component in .NET 9 contains a denial of service vulnerability due to incorrect input validation.
System administrators are advised to update PowerShell 7 to an unaffected version (see affected software).
Discussion
Please open a support question to discuss the PowerShell aspects of this advisory.
Please use dotnet/runtime#109738 for discussion of the .NET Runtime aspects this advisory.
Mitigation factors
Applications that do not use the NrbfDecoder component are not affected by this vulnerability. By default, PowerShell does reference this component.
Affected Software
The vulnerability affects PowerShell 7 prior to the following versions:
| PowerShell 7 Version | Affected version | Patched Version |
|---|---|---|
| 7.5 | <=7.5.0-rc.1 | 7.5.0 |
| 7.4 | Not Affected |
The vulnerability affects PowerShell when running on the following operating systems:
| Operating System | Affected |
|---|---|
| Windows | Yes |
| macOS | Yes |
| Linux | Yes |
Advisory FAQ
How do I know if I am affected?
If all of the following are true:
- Run
pwsh -v, then, check the version in the table in Affected Software to see if your version of PowerShell 7 is affected.
How do I update to an unaffected version?
Follow the instructions at Installing PowerShell 7 to install the latest version of PowerShell 7.
Updating PowerShell 7 using Microsoft Update
Updating PowerShell 7 using Microsoft Update
Other Information
Reporting Security Issues
If you have found a potential security issue in PowerShell 7,
please email details to secure@microsoft.com.
Support
You can ask questions about this issue on GitHub in the PowerShell organization.
This is located at https://github.com/PowerShell/.
The Announcements repo (https://github.com/PowerShell/Announcements)
will contain this bulletin as an issue and will include a link to a discussion issue where you can ask questions.
Disclaimer
The information provided in this advisory 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.
What if the update breaks my script or module?
You can uninstall the newer version of PowerShell 7 and install the previous version of PowerShell 7.
This should be treated as a temporary measure.
Therefore, the script or module should be updated to work with the patched version of PowerShell 7.
Acknowledgments
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure.
See acknowledgments for more information.
External Links
Revisions
V1.0 (January 28, 2025): Advisory published.
Version 1.0
Last Updated 2025-01-28