Many methods have been shown that could cause a denial of service situation in a GSM network.
While doing some research and tweaking the settings of my own network I accidentally came across a strange behaviour pattern my test phones seemed to be following. So I decided to read some chapters from the standard and it turned out that my phones do this intentionally - they follow the standard. After that it wasn’t really hard to put together all the pieces and create an attack scenario in which the target phone(s) will not have any signal until they are rebooted or have their SIM cards reinserted. It is important to note that this is a protocol based DoS, not simple jamming and as far as I know this particular vulnerability wasn’t presented anywhere else before. During the talk I will demonstrate the problem by introducing my creation called “LURD" which is capable of causing DoS for a massive amount of subscribers and could even fit into your pocket. At the end I won’t be able to tell you countermeasures (except the classic: don’t use GSM), instead I’m planning on giving some ideas why GSM-hacking is still something to tinker with even in today’s fast paced 3G-4G-5G world.