GFI Kerio Control Unsigned System Image Upload Root Code Execution

A remote code execution vulnerability in GFI Kerio Control 9.4.5 allows attackers with administrative access to upload and execute arbitrary code through the firmware upgrade feature. The system upgrade mechanism accepts unsigned .img files, which can be modified to include malicious scripts within the upgrade.sh or disk image components. These modified upgrade images are not validated for authenticity or integrity, and are executed by the system post-upload, enabling root access.

GFI Kerio Control GFIAgent Missing Authentication on Administrative Interfaces

A missing authentication vulnerability in the GFIAgent component of GFI Kerio Control 9.4.5 allows unauthenticated remote attackers to perform privileged operations. The GFIAgent service, responsible for integration with GFI AppManager, exposes HTTP services on ports 7995 and 7996 without proper authentication. The /proxy handler on port 7996 allows arbitrary forwarding to administrative endpoints when provided with an Appliance UUID, which itself can be retrieved from port 7995. This results in a complete authentication bypass, permitting access to sensitive administrative APIs.

GFI Kerio Control GFIAgent Authentication Bypass via Proxy Forwarding

An authentication bypass vulnerability exists in GFI Kerio Control 9.4.5 due to insecure default proxy configuration and weak access control in the GFIAgent service. The non-transparent proxy on TCP port 3128 can be used to forward unauthenticated requests to internal services such as GFIAgent, bypassing firewall restrictions and exposing internal management endpoints. This enables unauthenticated attackers to access the GFIAgent service on ports 7995 and 7996, retrieve the appliance UUID, and issue administrative requests via the proxy. Exploitation results in full administrative access to the Kerio Control appliance.

An issue was discovered in GFI Kerio Control 9.2.5 through 9.4.5. The dest GET parameter passed to the /nonauth/addCertException.cs and /nonauth/guestConfirm.cs and /nonauth/expiration.cs pages is not properly sanitized before being used to generate a Location HTTP header in a 302 HTTP response. This can be exploited to perform Open Redirect or HTTP Response Splitting attacks, which in turn lead to Reflected Cross-Site Scripting (XSS). Remote command execution can be achieved by leveraging the upgrade feature in the admin interface.

A DOM based XSS in GFI Kerio Control v9.3.0 allows embedding of malicious code and manipulating the login page to send back a victim's cleartext credentials to an attacker via a login/?reason=failure&NTLM= URI.