CVE-2022-23511 is a privilege escalation vulnerability affecting the Amazon CloudWatch Agent for Windows, specifically versions up to and including 1.247354. The CloudWatch Agent is a monitoring tool used to collect metrics and logs from Amazon EC2 instances and on-premises Windows servers. The vulnerability arises from improper handling of insufficient privileges (CWE-274) during the agent's repair process. When a user with administrative privileges on the affected Windows host triggers a repair of the CloudWatch Agent, a pop-up window is launched with SYSTEM-level permissions. This allows the user to spawn a new command prompt running under the NT AUTHORITY\SYSTEM account, effectively escalating their privileges from administrative to SYSTEM level. Exploitation requires that the attacker already has administrative access to the host and the ability to initiate the agent repair process, including installing any necessary tools to trigger the issue. This vulnerability does not impact the CloudWatch Agent versions for macOS or Linux. The vendor has addressed the issue in version 1.247355 of the CloudWatch Agent, and upgrading to this version is the only recommended remediation. No workarounds are available. There are no known exploits in the wild at this time. The vulnerability was published on December 12, 2022, and is classified as medium severity by the vendor. The root cause is improper privilege handling during the repair operation, which allows privilege escalation from administrative to SYSTEM level on Windows hosts running the affected agent versions.

For European organizations, this vulnerability poses a risk primarily in environments where the Amazon CloudWatch Agent for Windows is deployed on EC2 instances or on-premises Windows servers. The ability to escalate privileges from administrative to SYSTEM level can allow an attacker with initial administrative access to gain full control over the affected system, potentially leading to unauthorized access to sensitive data, modification of system configurations, or persistence mechanisms. This can undermine the confidentiality, integrity, and availability of critical monitoring infrastructure and the systems they observe. Given that administrative access is a prerequisite, the vulnerability mainly amplifies the impact of an existing compromise or insider threat rather than enabling initial access. However, in environments with shared administrative accounts or insufficient segregation of duties, this vulnerability could facilitate lateral movement and deeper infiltration. The lack of known exploits reduces immediate risk, but organizations should not be complacent as attackers often develop exploits post-disclosure. The impact is particularly significant for organizations relying heavily on Windows-based monitoring agents in hybrid cloud/on-premises setups, including financial institutions, critical infrastructure providers, and large enterprises common in Europe.

The primary and only effective mitigation is to upgrade the Amazon CloudWatch Agent for Windows to version 1.247355 or later. Organizations should implement a rapid patch management process to identify all Windows hosts running the affected agent versions and perform the upgrade promptly. Additionally, organizations should restrict administrative access to trusted personnel only and enforce the principle of least privilege to minimize the risk of exploitation. Monitoring and alerting on unusual repair process triggers or command prompt launches with SYSTEM privileges can help detect potential exploitation attempts. Implementing endpoint detection and response (EDR) solutions that can flag privilege escalation behaviors is also recommended. Network segmentation and strict access controls can limit the ability of attackers to reach affected hosts. Since no workarounds exist, organizations should prioritize patching and consider temporary compensating controls such as enhanced monitoring and auditing of administrative actions related to the CloudWatch Agent repair process.