Tutorial - OpenServer calserver

##
OpenServer calserver

Created 2/22/01
CVE 2000-0306

### Impact

A remote attacker could gain root access by exploiting a buffer overflow condition in the SCO OpenServer `calserver` service.

### Background

The SCO OpenServer operating system comes with a calendar service called `calserver`.

### The Problem

A buffer overflow in `calserver` could allow an attacker to execute arbitrary commands with root privileges. If `calserver` is running in local mode, the vulnerability could only be exploited by a user on the local machine, leading to a privilege-elevation attack. If `calserver` is running in remote mode, the vulnerability could be exploited remotely, leading to remote root access.

OpenServer 5.04 and earlier could be affected by this vulnerability if unpatched.

### Resolution

Upgrade to the latest version of OpenServer or install SCO patch SSE019.

### Where can I read more about this?

This vulnerability was reported in SCO Security Bulletin 99.02.