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 system fleet. Android 14 additionally introduces a characteristic 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 secure from community packet injection, tampering, or eavesdropping on consumer visitors. Android doesn’t depend on link-layer encryption to handle this risk mannequin. As a substitute, Android establishes that every one community visitors must be end-to-end encrypted (E2EE).
When a consumer connects to mobile networks for his or her communications (knowledge, 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 trying to connect with it. Attackers exploit this in a variety of methods, starting from visitors interception and malware sideloading, to classy 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 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 danger
The cellular ecosystem is quickly adopting 5G, the most recent wi-fi normal for cellular, and lots 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 system 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 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 degree of safety as subsequent cellular generations do. Most notably, 2G networks based mostly on the World System for Cell Communications (GSM) normal 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 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 most typical 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 doubtlessly sideloading Pegasus malware into journalist telephones to a subtle phishing scheme that allegedly impacted a whole bunch of hundreds of customers with a single FBS. This Stingray-based fraud assault, which doubtless downgraded system’s connections to 2G to inject SMSishing payloads, has highlighted the dangers of 2G connectivity.
To handle this danger, Android 12 launched a new characteristic that permits customers to disable 2G on the modem degree. Pixel 6 was the primary system to undertake this characteristic and it’s now supported by all Android units that conform to Radio HAL 1.6+. This characteristic was rigorously designed to make sure that customers usually are not impacted when making emergency calls.
Mitigating 2G safety dangers for enterprises
The trade acknowledged the numerous safety and privateness advantages and impression of this characteristic for at-risk customers, and we acknowledged how vital disabling 2G may be for our Android Enterprise clients.
Enterprises that use smartphones and tablets require robust safety to safeguard delicate knowledge and Mental Property. Android Enterprise gives strong administration controls for connectivity security capabilities, together with the flexibility to disable WiFi, Bluetooth, and even knowledge signaling over USB. Beginning in Android 14, enterprise clients and authorities businesses managing units utilizing Android Enterprise will have the ability to prohibit a tool’s capability to downgrade to 2G connectivity.
The 2G safety enterprise management in Android 14 permits our clients to configure cellular connectivity based on their danger mannequin, permitting them to guard their managed units from 2G visitors interception, Individual-in-the-Center assaults, and different 2G-based threats. IT directors can configure this safety as mandatory, at all times maintaining the 2G radio off or guaranteeing staff 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 via Android Enterprise. Android Enterprise additionally gives 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 consumer visitors is protected and E2EE by the Android platform, mobile networks expose circuit-switched voice and SMS visitors. These two explicit visitors sorts are strictly protected solely by the mobile hyperlink layer cipher, which is totally managed by the community with out transparency to the consumer. In different phrases, the community decides whether or not visitors is encrypted and the consumer has no visibility into whether or not it’s being encrypted.
Current studies recognized utilization of null ciphers in industrial networks, which exposes consumer voice and SMS visitors (comparable 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 visitors interception.
Android 14 introduces a consumer 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 tremendously enhance communication privateness for units that undertake the most recent radio {hardware} abstraction layer (HAL). We count on this new connectivity safety characteristic to be accessible in additional units over the following few years as it’s adopted by Android OEMs.
Persevering with to associate to lift the trade bar for mobile safety
Alongside our Android-specific work, the crew is often concerned within the improvement and enchancment of mobile safety requirements. We actively take part in requirements our bodies comparable to GSMA Fraud and Safety Group in addition to the third Era Partnership Undertaking (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 recent identification, 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 often associate with different inside Google groups as effectively, together with the Android Pink Workforce and our Vulnerability Rewards Program.
Furthermore, in alignment with Android’s openness in safety, we actively associate with high educational teams in mobile safety analysis. For instance, in 2022 we funded through our Android Safety and Privateness Analysis grant (ASPIRE) a undertaking to develop a proof-of-concept to judge mobile connectivity hardening in smartphones. The tutorial crew introduced the consequence of that undertaking 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 consumer communications, is a precedence on Android. With upcoming Android releases, we’ll proceed so as to add extra options to harden the platform in opposition to mobile safety threats.
We sit up for discussing the way forward for telco community safety with our ecosystem and trade companions and standardization our bodies. We will even proceed to associate with educational establishments to resolve complicated issues in community safety. We see super alternatives to curb FBS threats, and we’re excited to work with the broader trade to resolve them.
Particular because of our colleagues who had 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
