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This live blog contains information regarding vulnerabilities in the Microsoft Message Queuing service. As soon as we have an update, we’ll add it to this post. More information about possible risks and details can be found at the bottom of this blog. Last updated on April 14, 2023.
Update 14 April 2023
13:00 | During the patch Tuesday of April 2023, Microsoft has fixed three vulnerabilities in the Microsoft Message Queuing service. The most severe vulnerability of the three is registered as CVE-2023-21554 and allows a remote unauthenticated attacker to execute arbitrary code by sending a specially crafted network packet to the Microsoft Message Queueing service.
This relative unknown Microsoft component is part of the standard installation of Microsoft Exchange servers.
Microsoft has published security patches for the vulnerability. It is advised to apply the security patches as soon as possible. Additionally, it is advised not to expose the service on the internet.
Reason and background of this blog
This blog contains information about vulnerabilities, the possible risk and advice on how to prevent or limit damage. Below are the possible risks, details and background information.
Vulnerability information
During the patch Tuesday of April 2023, Microsoft has fixed three vulnerabilities in the Microsoft Message Queuing service. The most severe vulnerability of the three is registered as CVE-2023-21554 and allows a remote unauthenticated attacker to execute arbitrary code by sending a specially crafted network packet to the Microsoft Message Queueing service.
This relative unknown Microsoft component is part of the standard installation of Microsoft Exchange servers.
Microsoft has published security patches for the vulnerability. It is advised to apply the security patches as soon as possible. Additionally, it is advised not to expose the service on the internet.
Potential Risk
The vulnerability CVE-2023-21554 has a CVSS score of 9.8. The CVSS scale runs from 0 to 10. A score of 9.8 or higher is rare and implies a high risk of exploitation with high impact. CVE-2023-21554 is an unauthenticated remote code execution vulnerability.
The vulnerability can be exploited by sending a special crafted network packet to the Microsoft Message Queueing service on port 1801/TCP. Depending on the use case of the service, the impact can be significant. The Microsoft Message Queueing service is part of a standard Microsoft Exchange server installation.
Detail info
The vulnerability exists in all supported versions of Microsoft Windows with the Microsoft Message Queueing Service installed. Microsoft has published patches as part of the Patch Tuesday of April 2023. Additionally, it is advised not to publicly expose port 1801/TCP, which is used by the service.
More details can be found in the Microsoft update guide: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21554.
If any suspicious or malicious activity is detected in relation to this article, please contact T-CERT. The Tesorion Computer Emergency Response Team offers specialist support 24/7. In emergencies, we immediately conduct an initial assessment by telephone and do all we can to get the situation under control as soon as possible.
Sources
More information is available at:
- CheckPoint QueueJumper blog: https://research.checkpoint.com/2023/queuejumper-critical-unauthorized-rce-vulnerability-in-msmq-service/
- Microsoft update guide: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21554
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