Remote Code Execution in CGServiSign via OS Command Injection

CGServiSign, developed by Changing, is susceptible to an OS command injection vulnerability identified as CVE-2026-15027. This vulnerability allows an unauthenticated remote attacker to execute arbitrary OS commands on a victim's computer. The attack vector involves enticing a user to navigate to a malicious webpage, which subsequently leverages the local service interface of the CGServiSign software to inject and execute system-level commands. Given that this interaction occurs through a local service interface exposed to the browser, it presents a significant risk to workstations running the software, as the injected commands inherit the privileges of the service process, likely resulting in full system compromise for the affected host.

Impact

Successful exploitation of CVE-2026-15027 results in remote code execution on the victim's host. This grants the attacker the ability to install persistent malware, exfiltrate sensitive data, or move laterally within the victim's network. The scope of impact is limited to systems where CGServiSign is installed and active.

Recommendation

1. Inventory all endpoints to identify installations of Changing CGServiSign.
2. Restrict external network access to the local service interface if possible, or isolate affected hosts until a security patch is provided by Changing.
3. Implement endpoint monitoring to track unexpected child processes spawned by the CGServiSign service executable.

Impact