RealVNC

RealVNC is a company that provides remote access software. The software consists of a server and client application for the Virtual Network Computing (VNC) protocol to control another computer's screen remotely.

History

RealVNC Ltd. was founded by Andy Harter (CEO) and other members of the original VNC team at AT&T. For a desktop to desktop connection RealVNC runs on Windows, Mac OS X, and many Unix-like operating systems. A RealVNC client also runs on the Java platform and on the Apple iPhone, iPod touch and iPad and Google Android devices. A Windows-only client, VNC Viewer Plus is now available, designed to interface to the embedded server on Intel AMT chipsets found on Intel vPro motherboards.

For remote access to view one computer desktop on another, RealVNC comes in one of three editions:

1. Free Edition – free, open source version distributed under the GNU General Public License; runs on various flavors of Unix (Linux, Solaris, HP-UX, AIX) and versions of Windows prior to Windows Vista (i.e. Windows NT 4, 2000, XP, Server 2003) newer Windows operating systems must use the Personal or Enterprise editions.^[1] Note that users who wish to use this free version, as supplied by the realvnc.com site, may need (for example) to patch and compile the XFree86 source code by themselves, as the free binaries available for download are outdated and typically fail to operate in modern environments.^[2] Fortunately, almost all Linux distributions include an updated/customised version of the RealVNC free edition. For example, in Debian and its derivatives, the RealVNC server and client appear under the packages named vnc4server and xvnc4viewer, respectively.

1. Personal Edition – commercial version geared towards home or small-business users, with authentication and encryption, remote printing, chat and file transfer; only runs on Windows.
2. Enterprise Edition – commercial version geared towards enterprises, with enhanced authentication and encryption, remote printing, chat, file transfer and a deployment tool for Windows; runs on Windows, Mac OS X and various flavours of Linux and UNIX.

As of release 4.3 (released August 2007) separate versions of both the Personal and Enterprise editions exist for 32-bit and 64-bit systems. The (as of 2010^[update]) latest release (4.6) includes features such as HTTP proxy support, chat, an address book, remote printing, unicode support, and connection notification.

Client

RealVNC clients using vncviewer can run in full-screen mode; they use the F8 function-key as the default key for bringing up an options menu (which includes the option to, among other things, switch off full screen mode or to forward a Control-Alt-Delete key-sequence).

Server

Server component of RealVNC allows computer to be remotely controlled by another computer. The software can be installed for legitimate purposes, but it can also be installed from a remote location by an attacker with malicious intent. It is detected as RemoteAccess:Win32/RealVNC by Windows Defender.^[3]

Connectivity

RealVNC uses the RFB protocol. It defaults to TCP port 5900. When making a connection over the internet, the user must open this port in the local firewall as well as configure port forwarding to forward TCP Port 5900 (or the customized port respectively) to the local machine address if behind a NAT Router.

As an alternative, one can tunnel VNC through SSH, avoiding the opening of additional ports and automatically traversing the NAT router. SSH also provides encryption of the connection between the VNC server and viewer.

Limitations

Unicode is not supported for VNC version 3.x and lower so it is impossible to transfer clipboard text outside the Latin-1 character set. This is not a restriction on the non-GPL software sold by RealVNC.

The VNC protocol is pixel based. Although this leads to great flexibility (i.e.- any type of desktop can be displayed), it is often less efficient than solutions that have a better understanding of the underlying graphic layout like X11. Those protocols send graphic primitives or high level commands in a simpler form (i.e.- open window), whereas RFB just sends the raw pixel data.

References

1. ^ "VNC feature comparison". RealVNC Limited. http://www.realvnc.com/vnc/features.html. Retrieved 2012-3-27. 
2. ^ Adam Tkac, Red Hat (2008-02-04), VNC compilation against Xorg 1.4, "VNC-List Archives" at realvnc.com, http://www.realvnc.com/pipermail/vnc-list/2008-February/058615.html, retrieved 2008-09-26 
3. ^ Microsoft (2006-06-18), RemoteAccess:Win32/RealVNC, "Microsoft Corporation" at [1], http://www.microsoft.com/security/portal/Threat/Encyclopedia/Entry.aspx?name=RemoteAccess%3aWin32%2fRealVNC&threatid=7480, retrieved 2009-12-14 

External links

• RealVNC - Official site