http://www.theregister.co.uk/2014/04..._easy_to_hack/
EE and Three are very easy to access the voicemail. apparently. the problem stems from the fact that they use the caller ID as part or full authentication when calling the voicemail number.
Caller ID is easy to spoof, especially over VoIP. so you call the voicemail number with your caller ID set to the same as the victims and as far as it is concerned you are the victim. so it lets you straight in to the voicemail.
Vodafone was secure and O2 crapped out.
EE and Three are very easy to access the voicemail. apparently. the problem stems from the fact that they use the caller ID as part or full authentication when calling the voicemail number.
Caller ID is easy to spoof, especially over VoIP. so you call the voicemail number with your caller ID set to the same as the victims and as far as it is concerned you are the victim. so it lets you straight in to the voicemail.
Vodafone was secure and O2 crapped out.