News team jailed, phone hacking not fixed though

This week former News of the World executives were sentenced, most going to jail, for the British phone hacking scandal.

Noticeably absent from the trial and much of the media attention are the phone companies. Did they know their networks could be so systematically abused? Did they care?

In any case, the public has never been fully informed about how phones have been hacked. Speculation has it that phone hackers were guessing PIN numbers for remote voicemail access, typically trying birthdates and inappropriate PIN numbers like 0000 or 1234.

There is more to it

Those in the industry know that there are additional privacy failings in mobile networks, especially the voicemail service. It is not just in the UK either.

There are various reasons for not sharing explicit details on a blog like this and comments concerning such techniques can't be accepted.

Nonetheless, there are some points that do need to be made:

  • it is still possible for phones, especially voicemail, to be hacked on demand
  • an attacker does not need expensive equipment nor do they need to be within radio range (or even the same country) as their target
  • the attacker does not need to be an insider (phone company or spy agency employee)

Disable voicemail completely - the only way to be safe

The bottom line is that the only way to prevent voicemail hacking is to disable the phone's voicemail service completely. Voicemail is not really necessary given that most phones support email now. For those who feel they need it, consider running the voicemail service on your own private PBX using free software like Asterisk or FreeSWITCH. Some Internet telephony service providers also offer third-party voicemail solutions that are far more secure than those default services offered by mobile networks.

To disable voicemail, simply do two things:

  • send a letter to the phone company telling them you do not want any voicemail box in their network
  • in the mobile phone, select the menu option to disable all diversions, or manually disable each diversion one by one (e.g. disable forwarding when busy, disable forwarding when not answered, disable forwarding when out of range)