Improper Command Neutralization Leading to Remote Code Execution in HMS Networks Ewon Flexy and Cosy+ Devices

HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have improper neutralization of special elements used in an OS command allowing remote code execution by attackers with low privilege access on the gateway, provided the attacker has credentials.

Weak Cookie Entropy Enabling Password Brute‑Force on HMS Networks Ewon Flexy and Cosy+

HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have weak entropy for authentication cookies, allowing an attacker with a stolen session cookie to find the user password by brute-forcing an encryption parameter.

Unauthenticated HTTP Request Denial of Service on HMS Networks Devices

HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 allows unauthenticated attackers to cause a Denial of Service by using a specially crafted HTTP request that leads to a reboot of the device, provided they have access to the device's GUI.

Stack Buffer Overflow in HMS Networks Ewon Flexy and Cosy+ Firmware Enabling Remote Code Execution

HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have a stack buffer overflow that leads to a Denial of Service, which can also be exploited to achieve Unauthenticated Remote Code Execution.

All version of Ewon Flexy and Cosy prior to 14.1 use wildcards such as (*) under which domains can request resources. An attacker with local access and high privileges could inject scripts into the Cross-origin Resource Sharing (CORS) configuration that could abuse this vulnerability, allowing the attacker to retrieve limited confidential information through sniffing.

A non-persistent XSS (cross-site scripting) vulnerability exists in eWON Flexy and Cosy (all firmware versions prior to 14.1s0). An attacker could send a specially crafted URL to initiate a password change for the device. The target must introduce the credentials to the gateway before the attack can be successful.