Description

CGServiSign developed by Changing has a OS Command Injection vulnerability. Unauthenticated remote attackers can induce victims to visit a malicious web page and inject arbitrary OS commands through the local service interface, resulting in command execution on the victim's local computer.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-09-23T09:17:07.657Z",
  "pubdate": "2026-09-23T09:17:07.657Z",
  "executiveSummary": "CGServiSign, developed by Changing, contains an OS command injection vulnerability within its local service interface.\nThe vulnerability permits unauthenticated remote attackers to execute arbitrary system commands on a victim's host machine.\nExploitation is achieved by inducing a user to navigate to a malicious web page, which then interacts with the local service to inject and execute commands.\nThis flaw represents a critical security risk, as it allows remote attackers to bypass local security controls, execute code with the privileges of the service, and potentially achieve full system compromise.\nThe vulnerability resides in the local service interface, which lacks sufficient input validation and sanitization of user-supplied data transmitted from web-based sources.\nSuccessful exploitation requires no prior authentication, relying instead on client-side interaction via a compromised or malicious web origin.",
  "technicalDetails": "The vulnerability originates from the improper handling of requests processed by the CGServiSign local service interface. The service acts as a bridge between web applications and local host operations; however, it fails to sanitize inputs provided through its interface, allowing for the injection of arbitrary OS commands.\nThe attack flow begins when an unauthenticated attacker hosts a malicious web page containing a crafted payload. When a victim visits this page, the browser initiates a request to the local CGServiSign service.\nBecause the service interface is exposed to the local network or accessible via the localhost loopback address, it processes these requests without enforcing rigorous authentication or source validation. The injection occurs when the service passes unsanitized parameters from the web-based request directly into system shell calls or process execution functions.\nBy manipulating these parameters, an attacker can append malicious commands to the expected command execution flow. For example, if the service expects to execute a specific administrative or sign-related function, an attacker could inject command separators (such as ';', '&', or '|') to terminate the intended command and execute a secondary, unauthorized command of their choosing.\nSince the CGServiSign service typically runs with the privileges of the logged-in user or potentially with elevated service privileges, the injected commands are executed within that security context. This grants the attacker the ability to perform actions such as installing persistent backdoors, exfiltrating sensitive data, or traversing the local filesystem.\nThe primary root cause is the lack of strict input filtering and the dangerous practice of executing shell commands based on external, untrusted input originating from a web-based context. The absence of robust input validation mechanisms allows for the circumvention of standard interface boundaries, enabling arbitrary code execution on the victim's host."
}