CVE-2026-73752 in AOS-CX
Summary
by MITRE • 09/01/2026
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.
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Analysis
by VulDB Data Team • 09/01/2026
The identified vulnerability represents a critical security flaw within the Application Operating System for CX switches, specifically affecting its application programming interface endpoints. This issue is classified as an unauthenticated arbitrary file write vulnerability, meaning that no valid credentials or authentication tokens are required to trigger the exploit. The core technical failure lies in insufficient input validation and path traversal controls within the API handler logic. When a malicious actor sends a specially crafted HTTP request containing manipulated file paths or parameters, the system fails to sanitize these inputs properly. Consequently, the application writes data to arbitrary locations on the underlying operating system filesystem rather than restricting writes to designated temporary directories or specific configuration folders. This lack of strict boundary enforcement allows an attacker to overwrite critical system files, modify existing configurations, or create new executable scripts in accessible directories.
The operational impact of this vulnerability is severe due to its potential for remote code execution. By writing arbitrary content to the file system, an attacker can place a malicious script or binary in a location that is subsequently executed by privileged processes or scheduled tasks inherent to the switch's operation. Alternatively, overwriting configuration files such as shell profiles or service definitions can alter the behavior of the operating system to execute commands under elevated privileges. Since the vulnerability does not require authentication, it significantly lowers the barrier for entry, allowing any network-connected entity with access to the management interface to exploit this flaw. This effectively compromises the confidentiality, integrity, and availability of the network infrastructure managed by these switches, potentially leading to a complete takeover of the device and its use as a pivot point for further attacks within the internal network.
From a classification perspective, this vulnerability aligns closely with CWE-434, which describes the unrestricted upload of files with dangerous types or arbitrary file write vulnerabilities where user input is not properly validated before being written to disk. Furthermore, in terms of attack tactics and techniques, this exploitation path corresponds to ATT&CK technique T1505.002, known as Server Software Component: Web Shell, if the attacker writes a web shell for persistent access, or more broadly to T1059 Command and Scripting Interpreter via file creation mechanisms that lead to execution. The unauthenticated nature of the exploit also relates to CWE-347, Improper Verification of Cryptographic Signature, in contexts where API endpoints might rely on signature verification rather than strict authentication for certain operations, though the primary issue here is the lack of access control and input sanitization entirely.
Mitigation strategies must focus on immediate patching and network-level controls until updates are applied. Administrators should apply the latest firmware patches provided by the vendor to address this specific API endpoint flaw. In environments where patching cannot be performed immediately, it is crucial to restrict network access to the management interface of AOS-CX switches using strict firewall rules or Access Control Lists that limit connectivity to trusted IP addresses only. Additionally, implementing Web Application Firewalls with deep packet inspection capabilities can help detect and block requests containing suspicious file path patterns or known exploit signatures targeting this vulnerability. Regular auditing of API endpoint configurations and ensuring that all public-facing services adhere to the principle of least privilege are essential long-term practices to prevent similar arbitrary write vulnerabilities from being exploited in other systems.