Tuesday, July 9, 2024

Radiator 4.29 released!

We are pleased to announce the release of Radiator version 4.29. The latest release includes a major Radius protocol security fix, and the usual usability and interoperability improvements and bug fixes.

New usability improvements

  • Tested and supported for Ubuntu 24.04
  • AuthBy LDAP2 improvements
  • CEF and JSON logging fixes
  • Updates to address BlastRADIUS protocol vulnerability

    Radiator is actively engaged with IETF’s radext working group and we have been working under embargo to implement the fixes based on the work done in the group.

  • Add a new flag parameter LimitProxyState to Client clauses. This parameter allows dropping those requests from non-proxy clients that contain Proxy-State but do not contain Message-Authenticator. Ensure that ServeRADSEC drops requests with bad Message-Authenticator instead of just logging them. The upcoming Radius transport update by IETF's radext working group will remove the redundant signatures but keep them for the current transport profile. LimitProxyState addresses CVE-2024-3596.
  • Update RADIUS Message-Authenticator attribute handling. Message-Authenticator is always added as the first attribute in Radius messages. Message-Authenticator is now added automatically to replies to Access-Request messages and to Access-Request messages when they are proxied.
  • RequireMessageAuthenticator is now available for AuthBy RADIUS and its subclasses. It can be set for all hosts in an AuthBy or host-by-host basis. This parameter requires a valid Message-Authenticator in proxy replies.
  • A new configuration flag -no_message_authenticator is available in radpwtst to skip Message-Authenticator in Access-Requests.
  • Please see the security notice for more information on CVE-2024-3596 and our security recommendations.

    New attributes ensuring interoperability

  • Vendor specific attributes updated in the Radiator dictionary for Arista, Dell, ELTEK, Force10, Mojo, and Teldat.
  • More detailed changes can be found in the revision history. Radiator packages are available to download for current licensees from the downloads page and the Radiator repository.

    Would you like to know more?

    As always, you can contact Radiator team at info(a)radiatorsoftware.com - we are happy to learn more about your use case and assist you!

    Security Notice: BlastRADIUS protocol vulnerability (CVE-2024-3596) fixed in Radiator v4.29

    In February 2024 University of California San Diego researchers and their partners reported a vulnerability discovered in the RADIUS protocol to the CERT and IETF. The RADIUS protocol vulnerability was later named BlastRADIUS. The vulnerability allows the attacker to alter RADIUS messages between the RADIUS server and client so that for example a rejected authentication can be turned into accepted authentication. Utilising the vulnerability requires that the attacker is able replace the original requests and replies between RADIUS client and server with the attacker’s content. Only the RADIUS messages, which do not contain message authenticator, or where the RADIUS client or server is not verifying message authenticator properly, are vulnerable.

    Radiator Software has been working since February together with the researchers and other RADIUS server implementers to implement the identified fixes for RADIUS protocol in Radiator. This work and fixes have been under embargo until July 9th 2024 12:00am UTC. The fixes for RADIUS protocol have been implemented in the Radiator v4.29 released now after the embargo has ended.

    Affected Radiator versions

    Since this is a recently discovered RADIUS protocol vulnerability, all Radiator versions up until version 4.29 are affected.

    Affected Radiator configurations and deployments

    The RADIUS server deployments, which send and receive RADIUS requests without message authenticator or RadSec (RADIUS over TLS) over untrusted networks, are the most vulnerable for abuse. Enterprise Wi-Fi (EAP) authentication is using message authenticator in all messages by default so in those networks, the effect of the vulnerability depends if the RADIUS client implementation (e.g. in a Wi-Fi controller) is verifying the message authenticator properly. In addition to the RADIUS server updates, also RADIUS clients and client software may need to be updated.

    As Radiator implements the RADIUS protocol all Radiator configurations and deployments using RADIUS protocol without requiring Message Authenticator or RadSec (RADIUS over TLS) are affected by this vulnerability.


    Radiator Software strongly recommends upgrading Radiator to the latest version to get all the improvements and fixes to the vulnerability. In addition to upgrading Radiator, the Message-Authenticator requirement instructions should also be followed.

    Configuring Message-Authenticator requirement

    Requiring Message-Authenticator from RADIUS clients

    Radiator version 4.10 (2012) or newer can be configured to require a Message-Authenticator from a RADIUS client by adding RequireMessageAuthenticator to the Client configuration. For example:

         Identifier CLIENT-IPV4-
         Secret 6m9TXQTjLdH5BbgT

    Please note that configuring RequireMessageAuthenticator will require the Message-Authenticator to be present in the request and does not accept requests without it.

    A legacy RADIUS client, which is not able, or configured, to send Message-Authenticator is not able to connect with Radiator after this requirement. This server configuration directive also does not work alone as the RADIUS clients should be configured to use, require and verify the Message-Authenticator as well.

    By default Radiator proxies and responds with Message-Authenticator to all messages with Message-Authenticator already present in them, but accepts also requests without the Message-Authenticator for compatibility and interoperability reasons.

    Requiring Message-Authenticator from RADIUS proxies or servers

    Radiator v4.29 (2024) adds RequireMessageAuthenticator configuration directive for RADIUS based AuthBys such as AuthBy RADIUS, ROUNDROBIN and HASHBALANCE. With RequireMessageAuthenticator enabled, the AuthBy only accepts requests with Message-Authenticator in the RADIUS replies. Radiator by default adds Message-Authenticator to outgoing messages.

    <AuthBy RADIUS>
         Identifier AUTHBY-RADIUS-PROXIES
         Secret 9iLeKAnBP8e8oMhb
         Retries 1
         RetryTimeout 3
         FailureBackoffTime 5
         # Requires Message-Authenticator from all RADIUS proxies/servers in this AuthBy
              # RequireMessageAuthenticator can also be required per host
              AuthPort 1812
              AcctPort 1813
              # RequireMessageAuthenticator can also be required per host
              AuthPort 1812
              AcctPort 1813

    Requiring Message-Authenticator in requests with Proxy-State attribute

    Radiator v4.29 introduces an additional configuration directive, LimitProxyState, which can be added to NAS RADIUS client definitions to require a valid Message-Authenticator in all requests, which contain the Proxy-State attribute used in the BlastRADIUS attack. This allows requests without Message-Authenticator (e.g. RADIUS client does not support it) to be received, but prevents the BlastRADIUS attack by not accepting requests with Proxy-State included in them. This configuration directive should only be used for NAS RADIUS clients, e.g network equipment such as switches, Wi-Fi controllers etc. It should not be used for clients, which are RADIUS servers or proxies. An example of the configuration is below:

         Identifier CLIENT-IPV4-
         Secret 6m9TXQTjLdH5BbgT

    Limiting unencrypted RADIUS use only to management networks

    To utilise the vulnerability the attacker needs to get in between RADIUS servers or between RADIUS server and RADIUS client. Separating unencrypted RADIUS traffic into a management network and reducing the routing distance between the server and clients makes it more difficult to perform the actual attack.

    Unencrypted RADIUS over public networks exposes the RADIUS requests for the well-resourced attackers to abuse and should be avoided.

    Securing RADIUS messages with TLS or VPN

    The BlastRADIUS attack only works on unencrypted RADIUS traffic over UDP or TCP. The RADIUS traffic can already be secured with RADIUS over TLS (RadSec, RFC 6614) or with VPN solutions if RadSec support is not available.

    Radiator is the first RADIUS server ever (v3.12, 2005) to implement RADIUS over TLS neve(RadSec, RFC 6614), which was an IETF draft originally developed in cooperation between eduroam and Radiator implementers. Radiator Software continues to participate in developing the RADIUS over TLS specification in the IETF as well as implementing the latest features into the Radiator itself.

    Radiator Software strongly recommends migrating from unencrypted RADIUS to RADIUS over TLS. While requiring Message-Authenticator from RADIUS client and servers mitigates the vulnerability, the effort needed to configure these and test the changes, clients and servers for interoperability may be greater than configuring and deploying RADIUS over TLS to secure both the protocol and privacy of the information transferred in RADIUS request attributes.

    Questions and answers

    Is my multi-factor authentication (MFA/2FA) affected?

    If your multi-factor authentication is using RADIUS, it is likely to be affected. The exposure for the vulnerability depends on the RADIUS clients, servers and the attacker’s access to the network in between them. If your systems are for example doing MFA authentication with unencrypted RADIUS over the public Internet to a multi-factor authentication service provider your authentication is exposed and vulnerable. Is my enterprise Wi-Fi (WPA2/WPA3 Enterprise) affected?

    No. Enterprise Wi-Fi utilises EAP authentication over RADIUS. The EAP authentication already mandates Message-Authenticator in all requests.

    Is eduroam or OpenRoaming affected?

    No. Both eduroam and OpenRoaming are utilising EAP authentication like enterprise Wi-Fi (WPA2/WPA3) networks. OpenRoaming additionally mandates RadSec (RADIUS over TLS) and it is also supported in eduroam.

    Is my VPN solution affected?

    Similarly as with multi-factor authentication if your VPN endpoint is using unencrypted RADIUS for authenticating the VPN connection credentials from the RADIUS server or service, this vulnerability could be used in the worst case to allow an attacker to get a successful VPN connection to your network. Those VPN solutions which are using EAP authentication with RADIUS servers are not affected.

    Is roam.fi roaming service affected?

    The roam.fi roaming service is similar to eduroam and OpenRoaming utilising Enterprise Wi-Fi EAP authentication so it is not affected. Additionally roam.fi roaming service also supports RadSec (RADIUS over TLS) and it is strongly recommended that the roam.fi member organisations would migrate in using RadSec, when they have the RadSec connection capability themselves. The service will be updated to utilise Radiator v4.29 as soon as it becomes generally available.

    Is Radiator Auth.Fi RADIUS as a service affected?

    The Radiator Auth.Fi EAP authentication including both username-password and client certificate authentication is not affected.

    The captive portal and MAC address authentication used for guest network functionality is affected if unencrypted RADIUS connections are used. The Radiator Auth.Fi already supports RadSec client connections for securing the RADIUS traffic and it is strongly recommended that customers who have the ability to use RadSec, will switch to using RadSec instead of unencrypted RADIUS.

    The Radiator Auth.Fi Radiator will also be updated to utilise Radiator v4.29 as soon as it is released and that will enable additional options for adjusting Message-Authenticator settings for unencrypted RADIUS.

    Is my ISP, fixed line subscriber configuration provisioning or IP address allocation RADIUS solution affected?

    As these solutions are usually based on unencrypted RADIUS they are affected, but usually the RADIUS traffic is in these cases separated into management networks. If an attacker has access to a management network, the attacker is more likely to focus on more interesting targets than fabricating RADIUS requests and replies. The mitigation options work also in these networks, but extra attention should be given to testing, because the mitigation requires interoperable functionality from both RADIUS servers and clients.

    How can I update Radiator?

    If you have an active support contract for Radiator, you can get Radiator updates including the new Radiator v4.29 release from the Radiator download and repository page at https://radiatorsoftware.com/downloads/. If you are not sure or have an older license without a support contract, please contact sales@radiatorsoftware.com to renew your support.

    Is my RADIUS configuration affected?

    Radiator Software email support is able to answer questions and support you in case you want to evaluate the vulnerability’s effect on your deployment and use case. If you have active support, you can contact Radiator support at support@radiatorsoftware.com. If you are not sure or have an older license without a support contract or want to engage in larger scale configuration evaluation or upgrade, please contact sales@radiatorsoftware.com to renew your support or discuss the scope for Radiator expert services.

    For more information about the vulnerability

    BlastRADIUS WWW site: https://www.blastradius.fail/

    BlastRADIUS paper: https://www.blastradius.fail/pdf/radius.pdf

    CERT CVE: https://www.cve.org/CVERecord?id=CVE-2024-3596

    CERT Coordination Center: https://kb.cert.org/vuls/id/456537 (vendor status for vulnerability fixes)

    Radiator revision history (v4.29): https://radiatorsoftware.com/products/radiator/history/

    Wednesday, June 19, 2024

    How to speed up RADIUS authentication processing during peak hours with Radiator

    From time to time, our customers reach out to us and ask guidance on how to speed up RADIUS authentication processing during peak hours. Performance of this core functionality of Radiator is stable and predictable, and with increasing traffic load, most of the bottlenecks often emerge from the performance of the backend services that Radiator is utilising. In this blog, we give some helpful information to make improvements.

    What causes bottlenecks?

    In many cases,  authentication backends that Radiator is configured to use may be too slow to process the number of requests that are arriving. For example SQL databases may be slow to respond, LDAP lookups can take time, or HTTP requests be delayed. Writing accounting data or logging to a slow database can slow down Radiator.

    When this happens, the host system's UDP traffic buffer on the listening port fills up to the point that it overflows and new RADIUS request packets arriving at the server get dropped. Because the requests are dropped by the host operating system, they cannot even be logged as failed requests by Radiator.

    To get a better understanding of what is happening during peak hours, set `Trace 4` debug log level with `LogMicroseconds` in the configuration file (see [How to enable debug logging?]. The debug log will show how long each processing step is taking, and from there you can determine how many requests per second the configuration can handle.

    How to tune Radiator to speed up authentication processing?

    There are several ways to tune Radiator to speed up processing:

    • Split configuration into two separate files, one for authentication and one for accounting, and run Radiator as two separate running instances. This way there are two processes handling traffic with their own UDP buffers and backend dependencies that may even out the congestion. On Linux systems with systemd there are mechanisms readily available to help with that. More information: [How do I manage Radiator instances on a single host?].
    • Use a proxy instance to forward authentication and/or accounting requests to multiple worker instances (see first bullet). The requests can be spread out to worker instances so that request state is preserved (see [methods for load distribution and balancing] in documentation).
    • Within instances, use [FarmSize] to create a farm of server processes to add parallel processing of requests. Note: This is not compatible with many EAP protocols, such as EAP-TLS, EAP-TTLS, PEAP etc. This is because such protocols rely on authentication state being held within each server process, and it is necessary for all the requests for such protocols to go to the same Radiator process.
    • Incoming requests can be distributed from one or two proxying or load-balancing hosts to multiple hosts for processing.
    • Depending on use case, any combination of FarmSize, multiple instances per host and multiple hosts can be used together to enable more throughput. Separating processing on the Radiator side will create more separate connections to backends that may help even out backend load.
    Additionally, the bottleneck might be the available resources
    • If the host is running other processes, make sure it has enough resources available for Radiator. The best would be to use dedicated hosts for each function.
    • If a virtualisation platform is used, make sure that it can provide the configured resources to Radiator virtual machines even during the peak hours when other vm's are running their peak loads.
    • Logging to external servers may cause some unneeded delays for Radiator. This can be mitigated by configuring Radiator to log locally, and then process and ship logs with a separate agent.
    • Outside of Radiator, performance of backends may be tuned depending on the backend itself. For example a database can be scaled up or replicated to multiple-server cluster. On the other hand, speeding up the database might be possible even without adding more hardware if queries can be optimised or suitable indexes created. For optimising backends, please refer to their respective documentation.
    • Running configuration or Radiator may contain some parts that can be optimised. At the end of this blog post, we tell a bit about our consultation services. 
    How can we help?
    In case you would like our assistance when tuning your Radiator and related infrastructure, please contact sales@radiatorsoftware.com. Our team of experts have a long experience on configuring Radiator, and also assisting with the best practices when integrating Radiator with existing or new infrastructure. 

    Wednesday, June 12, 2024

    Radiator as a CISCO CPAR replacement

    Recently we have received a lot of queries on whether Radiator AAA would be a good solution for replacing Cisco CPAR (Cisco Prime Access Registrar). As it is known, Cisco CPAR has a released end of support date in October 2024, after which it will not receive software maintenance updates. Therefore many operators are looking to replace their existing CPAR setups with alternative established robust AAA solutions. If you are among these companies, Radiator AAA is the solution for you.

    Why choose Radiator AAA as a Cisco CPAR replacement?


    Known for its reliability and flexibility, Radiator AAA has been in the market for decades. Radiator is an actively developed and supported AAA server with RADIUS and TACACS+ functionalities. With modules focused on carriers, Radiator AAA can also be complemented with Diameter functionalities, SIM-based authentication with IMSI Privacy and other mobile network functionalities.

    At the same time, Radiator AAA Server offers support for both Linux and Windows installations - and Radiator AAA has multi-vendor support and can be installed flexibly on different platforms on physical or virtual machines. Radiator has extensive support for different databases and authentication backends (SQL-based, LDAP, AD etc.) as well as support for MFA solutions with TOTP capable authenticators and tokens (Google and MS authenticator, Yubikey, DIGIPASS etc.)

    The Radiator technical team consists of experts with vast experience in migration from other AAA solutions. We offer migration support and configuration assistance so you do not need to worry about meeting project schedules before the end of support for CPAR - we have already done these kinds of transitions. Radiator can integrate with existing databases and in most cases no changes to schema are needed.

    With Radiator, you can compile your AAA use cases under one product: RADIUS, Diameter, TACACS+, SIGTRAN, you name it, we have it!

    Want to know more?

    For any questions or other inquiries about Radiator as Cisco CPAR replacement, please contact sales@radiatorsoftware.com. We always provide also simple, transparent and cost-effective licensing models, so there will be no surprises in the cost of ownership during the whole time your company is using Radiator.

    Wednesday, May 22, 2024

    Meet Radiator team at WGC Americas in Dallas!

    Meet Radiator at WGC Dallas

    We are delighted to announce that Radiator Software will be attending the top connectivity event of the summer: WGC Americas in Dallas on 10 – 13 June 2024. We are looking forward to meeting our current and prospective partners and customers in Texas.

    Wireless Global Congress Americas

    WGC is hosted by the Wireless Broadband Alliance and gathers together Wi-Fi industry leaders and experts from all around the world. As usual, the event is divided into two parts: WBA Members-Only Sessions and plugfest on 10 and 11 June hosted by AT&T, and WGC Americas Open Congress on 12 and 13 June held in Dallas Marriott Downtown.

    Meet with Radiator team

    We extend an invitation to all WGC Americas attendees to meet with Radiator managing director Karri Huhtanen, who is part of our conference delegation. You can find the Radiator team at the WBA Members-Only Sessions and in the Open Congress throughout the event.

    To schedule a meeting or simply ask a question, please leave a message and we will get back to you. See you in Texas!

    Monday, May 20, 2024

    Radiator Simple WiFi Authentication – Introduction to Radiator Cloud

    We are pleased to announce an expansion to the Radiator product offering – Radiator Cloud for Azure. We have ever so often been approached by companies and organisations that require a fast to set up, easy to use hosted WiFi authentication solution.

    Often the trouble with Software-as-a-Service type WiFi solutions is the concern for privacy, who has access to customer data and how it is handled. To address the demand for a hosted solution with complete privacy to customer data, we’ve developed an Azure-native cloud solution – Radiator Cloud for Azure

    Radiator Cloud for Azure is a managed application that is deployed, hosted, operated and monitored all in Azure. User data and logs stay within your Azure tenant with no external access. User and NAS client provisioning is done with enhanced Azure UI and the solution can be monitored with premade Azure Monitoring queries.

    Radiator Simple WiFi authentication, powered by Radiator Cloud

    The first application that is now live in Azure Marketplace is Radiator Simple WiFi authentication. It is a simple username-password authentication solution that allows organisations to take control of their wireless network with minimum requirements. The only prerequisites to deploying the solution are an active Azure subscription and access to one’s network device configuration.

    Deployment is done within minutes from the Azure Marketplace. A user with at least Contributor permissions for their tenant can deploy the application. Provisioning and monitoring is made straightforward with Azure UI and billing is done together with the organisation's other Azure applications.

    Radiator Simple WiFi authentication – Easy, Fast and Affordable

    The main customer groups that benefit from the application are organisations who do not yet have any WiFi authentication solution in use, as well as organisations with multiple locations who want to centralise their WiFi authentication operations. Radiator Simple WiFi authentication provides an easy way for centralised user and device management with minimum prerequisites.

    Radiator Simple WiFi authentication is easy, fast and affordable. The simple structure of the application, backed with comprehensive deployment guide and user manual, make the application easy to deploy and operate. Deployment process is automated and does not need any vendor approval. Provisioning is very straightforward. In a typical deployment, you have a working system within the same day.

    The costs of the application consists of two parts: fixed monthly software cost and Azure running costs for hosting the application. All costs are transparent and easy to estimate. You are only billed by Azure, along with your other Azure applications.

    The future of Radiator Cloud

    While Radiator Simple WiFi authentication is already available for purchase in Azure Marketplace, we are also actively looking to expand the Radiator Cloud product family both horizontally with other use cases and vertically to other platforms.

    Our two big roadmap items for Radiator Cloud are enterprise-grade WiFi authentication application and an application for WiFi authentication utilising Microsoft Entra IDs. Both of these address a direct need not only from new but also existing customers who are looking to move from their existing Active Directory on to Azure.

    While these development news are all about Radiator Cloud, this is by no means a sign that we would have shifted focus from our on-site products. Radiator is committed to active development and latest standards and these efforts are made to make Radiator products more accessible to all organisations across different platforms and deployment models.

    Want to know more?

    If you have any questions about Radiator Simple WiFi Authentication or Radiator Cloud roadmap items, please do not hesitate to contact us at sales(a)radiatorsoftware.com

    Thursday, May 2, 2024

    WiFi offloading vs VoWiFi

    In recent years we have encountered a lot of customers wanting to utilize their networks more efficiently, and provide premium service for their subscribers. WiFi offloading and VoWiFi are popular ways to to extend the mobile operator’s network coverage into wifi, free bandwidth from congested cellular networks and improve user experience with better connectivity. The technologies share many similarities and both use a 3GPP AAA server for SIM based authentication.

    WiFi offloading offers some flexibility in the supported authentication backends and the SIM authentication can be done through various HSS and HLR interfaces depending on what the mobile operator has available. This is especially important in roaming scenarios where the WiFi provider has agreements with multiple MNOs to offload their subscribers.

    WiFi calling is more strictly standardised to support high QoS for the voice call, and also the handover between VoWiFi and VoLTE. This allows users to move outside the range of the WiFi hotspot and seamlessly continue the call over VoLTE, and vice versa.

    Let’s take a look at the key differences between the two related technologies:

    Comparison WiFi offloading VoWiFi
    Purpose Ease network congestion, Network CAPEX savings, Roaming cost savings, Secure authentication to private wireless networks: carrier, industrial, in-flight, underground, IoT Ease network congestion, Indoor coverage extension, Combat OTT apps, Roaming cost savings
    Relationship between MNO and access network provider Agreement required between MNO and wifi provider No relationship between MNO and wifi provider
    Access network Carrier or partner wifi Any public or private wifi
    Traffic Data only Voice and video calls
    SIM authentication protocol EAP-SIM, EAP-AKA, or EAP-AKA’ EAP-AKA
    Supported HSS interfaces SWx, Wx, Cx, S6a SWx required
    Supported HLR interfaces MAP, SIGTRAN Not supported
    ePDG Not applicable ePDG mandatory
    Security WPA Enterprise IPSec tunnel between UE and ePDG
    IMSI Privacy Yes, supported by Radiator Yes, supported by Radiator

    What is different?

    The main difference between WiFi offloading and VoWiFi is the relationship between the mobile operator and the wifi provider: operator controlled data offloading always requires a prior agreement between the MNO and the WISP. WiFi offloading is often done in high traffic areas such as airports, sports stadiums and concert venues, since offloading users to WiFi is cheaper than adding microcells to boost the mobile signal. MNOs can invest in carrier wifi hotspots themselves, or make offloading agreements with wireless ISPs.

    VoWiFi requires the mobile device to be connected to a wifi before attempting a VoWiFi call, but any type of wifi can be used for WiFi calling, including consumer home wifi. Therefore no relationship between the mobile operator and WiFi provider is required. However VoWiFi has specific technical requirements for the MNO: a HSS with SWx interface and ePDG are required.

    Private network authentication

    WiFi offloading technology is also applicable to private network offerings, such as industrial and IoT networks. SIM authentication provides a secure method to authenticate users into a private network using their SIM credentials and eliminates the human element of reusing and sharing passwords. In high security deployments the SIM authentication can be further combined with device IMEI check, to make sure that only authorised users and devices are able to access the private wifi network. VoWiFi is also possible in private networks, and can enable voice calls in challenging environments such as underground.

    Interested in WiFi offloading or VoWiFi?

    Radiator SIM Pack provides a fully featured 3GPP AAA server solution, with superb flexibility to connect with your environment. Please contact the Radiator team at sales (at) radiatorsoftware.com to get a quote.