Software Engineering Institute

CWE-288: Authentication Bypass Using an Alternate Path or Channel, and CWE-284: Improper Access Control - CVE-2015-0929

By visiting time.htm, a user is issued a cookie that grants administrative privileges in the Servision HVG web interface. There are two distinct impacts of this vulnerability:

1. An unauthenticated user is able to bypass authentication. This is addressed in firmware version 2.2.26a78 and later.
2. An authenticated user is able to elevate privileges. This is reportedly not addressed as of the current release, version 2.2.26a100.

A remote, unauthenticated user may be able to gain administrative privileges on the device.

Apply an upgrade

Users are encouraged to update their firmware to version 2.2.26a100.

Those unable to update should consider the following workaround.

Restrict access

As a general good security practice, only allow connections from trusted hosts and networks. Appropriate firewall rules which block incoming connections from untrusted networks would likely prevent an external attacker from accessing the device. Note that this does not address the issue of trusted, authenticated users accessing time.htm and gaining elevated privileges.