Description

An unauthenticated arbitrary file write vulnerability exists in an API endpoint of AOS-CX. Successful exploitation of this vulnerability allows an attacker to write arbitrary files to the underlying operating system, which could lead to remote code execution.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-09-01T21:18:41.757Z",
  "pubdate": "2026-09-01T21:18:41.757Z",
  "executiveSummary": "This vulnerability is an unauthenticated arbitrary file write flaw affecting the AOS-CX operating system. The vulnerability resides within an API endpoint that fails to properly sanitize or restrict file system access, allowing an unauthenticated remote attacker to write arbitrary files to the underlying host.\nThe primary risk associated with this vulnerability is the potential for Remote Code Execution (RCE). By overwriting configuration files, binary executables, or script files, an attacker can hijack the execution flow of the system. Given the nature of the AOS-CX architecture, successful exploitation provides the attacker with a persistent foothold, enabling full system compromise, data exfiltration, or the disruption of critical network services.\nThe vulnerability is critical due to the lack of authentication required for exploitation, meaning the attack surface is exposed to any network entity capable of communicating with the target API. No user interaction or specialized privileges are required to initiate the attack, making it a high-priority threat for organizations utilizing AOS-CX in exposed environments.",
  "technicalDetails": "The vulnerability originates from inadequate validation and input sanitization within an exposed API endpoint in AOS-CX. The affected component fails to enforce path restrictions, allowing an attacker to escape intended directories and perform write operations to sensitive locations within the underlying OS file system.\nThe exploitation flow begins when an unauthenticated attacker sends a crafted HTTP request to the vulnerable API endpoint. By manipulating specific parameters—typically those designated for file transfer or configuration management—the attacker forces the application to treat arbitrary input as a file system write operation. Because the endpoint lacks authentication mechanisms, it processes the request directly without verifying the sender's identity or authorization level.\nUpon receiving the request, the application fails to validate the destination file path. This path traversal or direct file write capability allows the attacker to specify target files such as startup scripts, binaries, or system configuration files (e.g., cron jobs or SSH authorized_keys files). The application, running with elevated privileges (typically root or service-level access), writes the attacker-supplied payload into the specified location on the underlying Linux-based file system.\nPost-exploitation, the attacker can leverage the overwritten files to gain Remote Code Execution. For instance, by overwriting a service binary or a periodic task script, the attacker ensures their malicious code is executed with the privileges of the modified service. This transition from a file write to RCE facilitates complete control over the network device, allowing for the installation of persistent backdoors, modification of routing tables, or interception of sensitive network traffic.\nThe susceptibility to this exploit is universal across all configurations where the management interface is accessible via the network. Since the vulnerability resides at the API level, standard network segmentation is the only immediate defense if internal controls are not strictly enforced. The underlying issue highlights a lack of secure coding practices regarding input handling and authorization enforcement within the management plane of the AOS-CX ecosystem."
}