CVE-2025-9039

We identified an issue in the Amazon ECS agent where, under certain conditions, an introspection server could be accessed off-host by another instance if the instances are in the same security group or if their security groups allow incoming connections that include the port where the server is hosted. This issue does not affect instances where the option to allow off-host access to the introspection server is set to 'false'. This issue has been addressed in ECS agent version 1.97.1. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. If customers cannot update to the latest AMI, they can modify the Amazon EC2 security groups to restrict incoming access to the introspection server port (51678).

Information Disclosure in Amazon ECS Container Agent in github.com/aws/amazon-ecs-agent

**Summary** [Amazon Elastic Container Service (Amazon ECS)](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/Welcome.html) is a fully managed container orchestration service that enables customers to deploy, manage, and scale containerized applications. Amazon ECS container agent provides an [introspection API](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/introspection-diag.html) that provides information about the overall state of the Amazon ECS agent and the container instances. We identified CVE-2025-9039, an issue in the Amazon ECS agent. **Impact** Under certain conditions, this issue could allow an introspection server to be accessed off-host by another instance if the instances are in the same security group or if their security groups allow incoming connections that include the port where the server is hosted. This issue does not affect instances where the option to allow off-host access to the introspection server is set to 'false'. Impacted versions: version 0.0.3 through 1.97.0 **Patches** This issue has been addressed in ECS agent version 1.97.1. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. **Workarounds** Customers who cannot update to the latest AMI can modify the Amazon EC2 security groups to restrict incoming access to the introspection server port (51678). **References** If you have any questions or comments about this advisory, we ask that you contact AWS Security via our [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [[email protected]](mailto:[email protected]). Please do not create a public GitHub issue.

Identificamos un problema en el agente de Amazon ECS que, bajo ciertas circunstancias, permitía que otra instancia accediera a un servidor de introspección fuera del host si las instancias pertenecían al mismo grupo de seguridad o si sus grupos de seguridad permitían conexiones entrantes que incluían el puerto donde se alojaba el servidor. Este problema no afecta a las instancias donde la opción para permitir el acceso externo al servidor de introspección estaba configurada como "false". Este problema se solucionó en la versión 1.97.1 del agente de ECS. Recomendamos actualizar a la última versión y asegurarse de que cualquier código derivado o bifurcado cuente con las nuevas correcciones. Si los clientes no pueden actualizar a la AMI más reciente, pueden modificar los grupos de seguridad de Amazon EC2 para restringir el acceso entrante al puerto del servidor de introspección (51678).