5G commercial networks are starting to roll out, promising exciting new use cases like automated cars and smart sensor networks. Many of the security protocols and algorithms for 5G are being ported from the previous 4G standard. Researchers have found that in 5G, as with 4G, the device capability information is sent to the base station before any security is layered onto the connection. This enables three kinds of attacks: Mobile network mapping (MNmap); bidding down; and battery drain on narrowband Internet of Things (NB IoT) devices.
Source: https://threatpost.com/5g-security-flaw-mitm-targeted-attacks/147073/