Cybersecurity researchers have found a contemporary set of safety points within the Terrestrial Trunked Radio (TETRA) communications protocol, together with in its proprietary end-to-end encryption (E2EE) mechanism that exposes the system to replay and brute-force assaults, and even decrypt encrypted site visitors.
Particulars of the vulnerabilities – dubbed 2TETRA:2BURST – had been introduced on the Black Hat USA safety convention final week by Midnight Blue researchers Carlo Meijer, Wouter Bokslag, and Jos Wetzels.
TETRA is a European cellular radio normal that is extensively utilized by legislation enforcement, army, transportation, utilities, and important infrastructure operators. It was developed by the European Telecommunications Requirements Institute (ETSI). It encompasses 4 encryption algorithms: TEA1, TEA2, TEA3, and TEA4.
The disclosure comes a bit over two years after the Netherlands-based cybersecurity firm found a set of safety vulnerabilities in TETRA normal known as TETRA:BURST, counting what was described as an “intentional backdoor” that may very well be exploited to leak delicate data.
The newly found points relate to a case of packet injection in TETRA, in addition to an inadequate repair for CVE-2022-24401, one of many 5 TETRA:BURST points, to stop keystream restoration assaults. The recognized points are listed beneath –
- CVE-2025-52940 – TETRA end-to-end encrypted voice streams are weak to replay assault. Moreover, an attacker with no information of the important thing could inject arbitrary voice streams, which are performed again indistinguishably from genuine site visitors by authentic name recipients.
- CVE-2025-52941 – TETRA end-to-end encryption algorithm ID 135 refers to an deliberately weakened AES-128 implementation which has its efficient site visitors key entropy decreased from 128 to 56 bits, rendering it weak to brute-force assaults.
- CVE-2025-52942 – Finish-to-end encrypted TETRA SDS messages function no replay safety, permitting for arbitrary replay of messages in the direction of both people or machines.
- CVE-2025-52943 – TETRA networks that help a number of Air Interface Encryption algorithms are weak to key restoration assaults because the SCK/CCK community secret is equivalent for all supported algorithms. When TEA1 is supported, an simply recovered TEA1 key (CVE-2022-24402) can be utilized to decrypt or inject TEA2 or TEA3 site visitors on the community.
- CVE-2025-52944 – The TETRA protocol lacks message authentication and subsequently permits for the injection of arbitrary messages resembling voice and information.
- ETSI’s repair for CVE-2022-24401 is ineffective within the prevention of keystream restoration assaults (No CVE, assigned a placeholder identifier MBPH-2025-001)
Midnight Blue mentioned the influence of the 2TETRA:2BURST depend upon the use-cases and configuration elements of every explicit TETRA community, and that networks that use TETRA in a data-carrying capability are significantly prone to packet injection assaults, doubtlessly permitting attackers to intercept radio communications and inject malicious information site visitors.
“Voice replay or injection situations (CVE-2025-52940) may cause confusion amongst authentic customers, which can be utilized as an amplifying think about a larger-scale assault,” the corporate mentioned. “TETRA E2EE customers (additionally these not utilizing Sepura Embedded E2EE) ought to in any case validate whether or not they could be utilizing the weakened 56-bit variant (CVE-2025-52941).”
“Downlink site visitors injection is usually possible utilizing plaintext site visitors, as we discovered radios will settle for and course of unencrypted downlink site visitors even on encrypted networks. For uplink site visitors injection, the keystream must be recovered.”
There isn’t a proof of those vulnerabilities being exploited within the wild. That mentioned, there are not any patches that tackle the shortcomings, except MBPH-2025-001, for which a repair is anticipated to be launched.
Mitigations for different flaws are listed beneath –
- CVE-2025-52940, CVE-2025-52942 – Migrate to scrutinized, safe E2EE resolution
- CVE-2025-52941 – Migrate to non-weakened E2EE variant
- CVE-2025-52943 – Disable TEA1 help and rotate all AIE keys
- CVE-2025-52944 – When utilizing TETRA in an information carrying capability: add TLS/VPN layer on high of TETRA
“If you happen to function or use a TETRA community, you’re actually affected by CVE-2025-52944, through which we show it is attainable to inject malicious site visitors right into a TETRA community, even with authentication and/or encryption enabled,” Midnight Blue mentioned.
“Additionally, CVE-2022-24401 probably impacts you, because it permits adversaries to gather keystream for both breach of confidentiality or integrity. If you happen to function a multi-cipher community, CVE-2025-52943 poses a vital safety threat.”
In a press release shared with WIRED, ETSI mentioned the E2EE mechanism utilized in TETRA-based radios will not be a part of the ETSI normal, including it was produced by The Vital Communications Affiliation’s (TCCA) safety and fraud prevention group (SFPG). ETSI additionally famous that purchasers of TETRA-based radios are free to deploy different options for E2EE on their radios.
The findings additionally coincide with the invention of three flaws within the Sepura SC20 collection of cellular TETRA radios that enable attackers with bodily entry to the gadget to attain unauthorized code execution –
- CVE-2025-52945 – Faulty file administration restrictions
- CVE-2025-8458 – Inadequate key entropy for SD card encryption
- Exfiltration of all TETRA and TETRA E2EE key supplies except the device-specific key Ok (no CVE, assigned a placeholder identifier MBPH-2025-003)
Patches for CVE-2025-52945 and CVE-2025-8458 are anticipated to be made out there within the third quarter of 2025, necessitating that customers are suggested to implement enhanced TETRA key administration insurance policies. MBPH-2025-003, then again, can’t be remediated resulting from architectural limitations.
“The vulnerabilities allow an attacker to achieve code execution on a Sepura Gen 3 gadget,” the corporate mentioned. “Assault situations that includes CVE-2025-8458 contain persistent code execution by entry to a tool’s SD card. Abuse of CVE-2025-52945 is much more easy because it requires solely temporary entry to the gadget’s PEI connector.”
“From the premise of code execution, a number of assault situations are viable, resembling exfiltration of TETRA key supplies (MBPH-2025-003) or the implantation of a persistent backdoor into the radio firmware. This results in the lack of confidentiality and integrity of TETRA communications.”
