CVE-2026-2999

Step 1: Target Identification: The attacker identifies systems running the vulnerable IDExpert Windows Logon Agent.

Step 2: Payload Hosting: The attacker sets up a malicious server hosting a specially crafted executable file (payload).

Step 3: Triggering the Vulnerability: The attacker sends a crafted request to the IDExpert Windows Logon Agent, instructing it to download the malicious executable from the attacker's server.

Step 4: File Download: The vulnerable agent downloads the attacker-controlled executable file.

Step 5: Execution: The agent, due to insufficient validation, executes the downloaded malicious executable with the privileges of the agent, resulting in RCE and system compromise.

The vulnerability stems from a flaw in the IDExpert Windows Logon Agent's handling of downloaded executable files. Specifically, the agent fails to properly validate the source or integrity of the downloaded files before execution. This allows an attacker to control the download location and content, leading to arbitrary code execution. The root cause likely involves insecure deserialization or a lack of input validation on parameters controlling file download and execution paths. The agent likely uses a privileged context, granting the attacker elevated privileges upon successful exploitation. The lack of proper authentication further exacerbates the issue, enabling any remote attacker to trigger the vulnerability.