Android is the primary cellular working system to introduce superior mobile safety mitigations for each customers and enterprises. Android 14 introduces help for IT directors to disable 2G help of their managed system fleet. Android 14 additionally introduces a function that disables help for null-ciphered mobile connectivity.

Hardening community safety on Android

The Android Safety Mannequin assumes that each one networks are hostile to maintain customers secure from community packet injection, tampering, or eavesdropping on person site visitors. Android doesn’t depend on link-layer encryption to handle this risk mannequin. As an alternative, Android establishes that each one community site visitors needs to be end-to-end encrypted (E2EE).

When a person connects to mobile networks for his or her communications (information, voice, or SMS), because of the distinctive nature of mobile telephony, the hyperlink layer presents distinctive safety and privateness challenges. False Base Stations (FBS) and Stingrays exploit weaknesses in mobile telephony requirements to trigger hurt to customers. Moreover, a smartphone can not reliably know the legitimacy of the mobile base station earlier than making an attempt to connect with it. Attackers exploit this in numerous methods, starting from site visitors interception and malware sideloading, to stylish dragnet surveillance.

Recognizing the far reaching implications of those assault vectors, particularly for at-risk customers, Android has prioritized hardening mobile telephony. We’re tackling well-known insecurities such because the threat introduced by 2G networks, the chance introduced by null ciphers, different false base station (FBS) threats, and baseband hardening with our ecosystem companions.

2G and a historical past of inherent safety threat

The cellular ecosystem is quickly adopting 5G, the most recent wi-fi commonplace for cellular, and lots of carriers have began to show down 2G service. In the USA, for instance, most main carriers have shut down 2G networks. Nonetheless, all current cellular units nonetheless have help for 2G. Because of this, when out there, any cellular system will hook up with a 2G community. This happens robotically when 2G is the one community out there, however this may also be remotely triggered in a malicious assault, silently inducing units to downgrade to 2G-only connectivity and thus, ignoring any non-2G community. This habits occurs no matter whether or not native operators have already sundown their 2G infrastructure.

2G networks, first applied in 1991, don’t present the identical stage of safety as subsequent cellular generations do. Most notably, 2G networks primarily based on the International System for Cellular Communications (GSM) commonplace lack mutual authentication, which permits trivial Individual-in-the-Center assaults. Furthermore, since 2010, safety researchers have demonstrated trivial over-the-air interception and decryption of 2G site visitors.

The out of date safety of 2G networks, mixed with the power to silently downgrade the connectivity of a tool from each 5G and 4G all the way down to 2G, is the most typical use of FBSs, IMSI catchers and Stingrays.

Stingrays are obscure but very highly effective surveillance and interception instruments which have been leveraged in a number of eventualities, starting from doubtlessly sideloading Pegasus malware into journalist telephones to a subtle phishing scheme that allegedly impacted a whole bunch of 1000’s of customers with a single FBS. This Stingray-based fraud assault, which possible downgraded system’s connections to 2G to inject SMSishing payloads, has highlighted the dangers of 2G connectivity.

To deal with this threat, Android 12 launched a new function that allows customers to disable 2G on the modem stage. Pixel 6 was the primary system to undertake this function and it’s now supported by all Android units that conform to Radio HAL 1.6+. This function was rigorously designed to make sure that customers should not impacted when making emergency calls.

Mitigating 2G safety dangers for enterprises

The business acknowledged the numerous safety and privateness advantages and influence of this function for at-risk customers, and we acknowledged how vital disabling 2G is also for our Android Enterprise prospects.

Enterprises that use smartphones and tablets require robust safety to safeguard delicate information and Mental Property. Android Enterprise offers strong administration controls for connectivity security capabilities, together with the power to disable WiFi, Bluetooth, and even information signaling over USB. Beginning in Android 14, enterprise prospects and authorities businesses managing units utilizing Android Enterprise will have the ability to limit a tool’s means to downgrade to 2G connectivity.

The 2G safety enterprise management in Android 14 permits our prospects to configure cellular connectivity in keeping with their threat mannequin, permitting them to guard their managed units from 2G site visitors interception, Individual-in-the-Center assaults, and different 2G-based threats. IT directors can configure this safety as mandatory, all the time protecting the 2G radio off or guaranteeing staff are protected when touring to particular high-risk areas.

These new capabilities are a part of the excellent set of 200+ administration controls that Android offers IT directors via Android Enterprise. Android Enterprise additionally offers complete audit logging with over 80 occasions together with these new administration controls. Audit logs are a vital a part of any group’s safety and compliance technique. They supply an in depth report of all exercise on a system, which can be utilized to trace down unauthorized entry, determine safety breaches, and troubleshoot system issues.

Additionally in Android 14

The upcoming Android launch additionally tackles the chance of mobile null ciphers. Though all IP-based person site visitors is protected and E2EE by the Android platform, mobile networks expose circuit-switched voice and SMS site visitors. These two specific site visitors varieties are strictly protected solely by the mobile hyperlink layer cipher, which is absolutely managed by the community with out transparency to the person. In different phrases, the community decides whether or not site visitors is encrypted and the person has no visibility into whether or not it’s being encrypted.

Current reviews recognized utilization of null ciphers in industrial networks, which exposes person voice and SMS site visitors (similar to One-Time Password) to trivial over the air interception. Furthermore, some industrial Stingrays present performance to trick units into believing ciphering will not be supported by the community, thus downgrading the connection to a null cipher and enabling site visitors interception.

Android 14 introduces a person choice to disable help, on the modem-level, for null-ciphered connections. Equally to 2G controls, it’s nonetheless doable to put emergency calls over an unciphered connection. This performance will enormously enhance communication privateness for units that undertake the most recent radio {hardware} abstraction layer (HAL). We anticipate this new connectivity safety function to be out there in additional units over the subsequent few years as it’s adopted by Android OEMs.

Persevering with to associate to boost the business bar for mobile safety

Alongside our Android-specific work, the group is recurrently concerned within the improvement and enchancment of mobile safety requirements. We actively take part in requirements our bodies similar to GSMA Fraud and Safety Group in addition to the third Technology Partnership Venture (3GPP), notably its safety and privateness group (SA3). Our long-term purpose is to render FBS threats out of date.

Particularly, Android safety is main a brand new initiative inside GSMA’s Fraud and Safety Group (FASG) to discover the feasibility of contemporary id, belief and entry management methods that will allow radically hardening the safety of telco networks.

Our efforts to harden mobile connectivity undertake Android’s defense-in-depth technique. We recurrently associate with different inside Google groups as effectively, together with the Android Crimson Staff and our Vulnerability Rewards Program.

Furthermore, in alignment with Android’s openness in safety, we actively associate with high tutorial teams in mobile safety analysis. For instance, in 2022 we funded by way of our Android Safety and Privateness Analysis grant (ASPIRE) a challenge to develop a proof-of-concept to guage mobile connectivity hardening in smartphones. The educational group introduced the consequence of that challenge within the final ACM Convention on Safety and Privateness in Wi-fi and Cellular Networks.

The safety journey continues

Consumer safety and privateness, which incorporates the protection of all person communications, is a precedence on Android. With upcoming Android releases, we are going to proceed so as to add extra options to harden the platform towards mobile safety threats.

We look ahead to discussing the way forward for telco community safety with our ecosystem and business companions and standardization our bodies. We may also proceed to associate with tutorial establishments to resolve advanced issues in community safety. We see great alternatives to curb FBS threats, and we’re excited to work with the broader business to resolve them.

Particular due to our colleagues who have been instrumental in supporting our mobile community safety efforts: Nataliya Stanetsky, Robert Greenwalt, Jayachandran C, Gil Cukierman, Dominik Maier, Alex Ross, Il-Sung Lee, Kevin Deus, Farzan Karimi, Xuan Xing, Wes Johnson, Thiébaud Weksteen, Pauline Anthonysamy, Liz Louis, Alex Johnston, Kholoud Mohamed, Pavel Grafov