Android is the primary cellular working system to introduce superior mobile safety mitigations for each customers and enterprises. Android 14 introduces assist for IT directors to disable 2G assist of their managed machine fleet. Android 14 additionally introduces a function that disables assist for null-ciphered mobile connectivity.
Hardening community safety on Android
The Android Safety Mannequin assumes that every one networks are hostile to maintain customers protected 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 every one community site visitors ought 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’t reliably know the legitimacy of the mobile base station earlier than trying to hook up with it. Attackers exploit this in a variety of 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 danger offered by 2G networks, the danger offered by null ciphers, different false base station (FBS) threats, and baseband hardening with our ecosystem companions.
2G and a historical past of inherent safety danger
The cellular ecosystem is quickly adopting 5G, the newest wi-fi normal for cellular, and plenty of carriers have began to show down 2G service. In the US, for instance, most main carriers have shut down 2G networks. Nevertheless, all current cellular units nonetheless have assist for 2G. Consequently, when accessible, any cellular machine will connect with a 2G community. This happens robotically when 2G is the one community accessible, however this can be remotely triggered in a malicious assault, silently inducing units to downgrade to 2G-only connectivity and thus, ignoring any non-2G community. This conduct 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 World System for Cell Communications (GSM) normal lack mutual authentication, which allows trivial Particular person-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 flexibility to silently downgrade the connectivity of a tool from each 5G and 4G all the way down to 2G, is the commonest use of FBSs, IMSI catchers and Stingrays.
Stingrays are obscure but very highly effective surveillance and interception instruments which were leveraged in a number of situations, starting from probably 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 probably downgraded machine’s connections to 2G to inject SMSishing payloads, has highlighted the dangers of 2G connectivity.
To handle this danger, Android 12 launched a new function that allows customers to disable 2G on the modem stage. Pixel 6 was the primary machine to undertake this function and it’s now supported by all Android units that conform to Radio HAL 1.6+. This function was fastidiously 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 affect of this function for at-risk customers, and we acknowledged how crucial 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 gives sturdy administration controls for connectivity security capabilities, together with the flexibility to disable WiFi, Bluetooth, and even information signaling over USB. Beginning in Android 14, enterprise prospects and authorities companies managing units utilizing Android Enterprise will have the ability to limit a tool’s potential to downgrade to 2G connectivity.
The 2G safety enterprise management in Android 14 allows our prospects to configure cellular connectivity in accordance with their danger mannequin, permitting them to guard their managed units from 2G site visitors interception, Particular person-in-the-Center assaults, and different 2G-based threats. IT directors can configure this safety as mandatory, at all times retaining the 2G radio off or guaranteeing workers are protected when touring to particular high-risk areas.
These new capabilities are a part of the great set of 200+ administration controls that Android gives IT directors by Android Enterprise. Android Enterprise additionally gives complete audit logging with over 80 occasions together with these new administration controls. Audit logs are a crucial a part of any group’s safety and compliance technique. They supply an in depth document 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 danger 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 sorts 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.
Latest stories recognized utilization of null ciphers in business networks, which exposes person voice and SMS site visitors (reminiscent of One-Time Password) to trivial over the air interception. Furthermore, some business 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 assist, 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 drastically enhance communication privateness for units that undertake the newest radio {hardware} abstraction layer (HAL). We count on this new connectivity safety function to be accessible in additional units over the following few years as it’s adopted by Android OEMs.
Persevering with to accomplice to boost the business bar for mobile safety
Alongside our Android-specific work, the group is frequently concerned within the improvement and enchancment of mobile safety requirements. We actively take part in requirements our bodies reminiscent of GSMA Fraud and Safety Group in addition to the third Technology Partnership Undertaking (3GPP), notably its safety and privateness group (SA3). Our long-term purpose is to render FBS threats out of date.
Specifically, Android safety is main a brand new initiative inside GSMA’s Fraud and Safety Group (FASG) to discover the feasibility of recent id, belief and entry management strategies that will allow radically hardening the safety of telco networks.
Our efforts to harden mobile connectivity undertake Android’s defense-in-depth technique. We frequently accomplice with different inner Google groups as nicely, together with the Android Crimson Workforce and our Vulnerability Rewards Program.
Furthermore, in alignment with Android’s openness in safety, we actively accomplice with prime educational teams in mobile safety analysis. For instance, in 2022 we funded by way of our Android Safety and Privateness Analysis grant (ASPIRE) a venture to develop a proof-of-concept to guage mobile connectivity hardening in smartphones. The tutorial group offered the end result of that venture within the final ACM Convention on Safety and Privateness in Wi-fi and Cell Networks.
The safety journey continues
Consumer safety and privateness, which incorporates the security 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 sit up for discussing the way forward for telco community safety with our ecosystem and business companions and standardization our bodies. We can even proceed to accomplice with educational establishments to unravel advanced issues in community safety. We see great alternatives to curb FBS threats, and we’re excited to work with the broader business to unravel 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
