Shell Control Box
Shell Control Box (SCB)[1] is a device for controlling and monitoring administrative protocols used for remote access or management in computer technology. SCB is a Linux based device developed by Balabit IT Security and based on Zorp technology. SCB inspects remote access protocols such as SSH, RDP, Telnet, or Vnc protocols. It can act as a transparent device (as a Router or a Network switch) an also in different non-transparent ways (jumpserver). Since 2009 SCB was re-branded by Tectia[2] under the name SSH Tectia Guardian[3]
Functions
SCB controls only administrative protocols with the embedded application layer gateway (proxy) technology.
Access control at the connection layer
Enforced policy controls classical network access control mechanisms: source IP, destination IP/port and protocol enforcement by layer 7 protocol analysis. It also controls user IDs (e.g. root or Administrator is prohibited) by classical blacklisting or whitelisting.
Advanced authentication and authorization
SCB supports gateway authentication, which is a two factor authentication served by SCB: users initiate connections and they also have to log in to SCB and enable their own connections.
SCB also supports four eyes principle, when users who log in must differ from enabler user. It ensures the user cannot log in without permission.
Channel Control
RDP and SSH protocols implements channels on the top of connection layer. Each SSH and RDP functions are performed in dedicated channels such as Shell is in Session shell channel or Drawing is the channel of Desktop forward in RDP. SCB implements an advanced control on channels enabled to use. It is useful for disabling port forwards, copy&paste and such other functions.
Audit and forensics tool
Inspected protocol content can be stored in a record, called Audit trail, and could be replayed by the Audit Player tool. Audit trail can be used as a digital evidence. As the whole connection can be replayed (seen by any auditor who have access to the device) it rises some privacy problems in different countries.