Cybersecurity researchers have found a recent 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 cell radio commonplace that is extensively utilized by regulation 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 slightly over two years after the Netherlands-based cybersecurity firm found a set of safety vulnerabilities in TETRA commonplace referred to as TETRA:BURST, counting what was described as an “intentional backdoor” that might be exploited to leak delicate info.
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 forestall 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 might inject arbitrary voice streams, which might be 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 characteristic no replay safety, permitting for arbitrary replay of messages in direction of both people or machines.
- CVE-2025-52943 – TETRA networks that assist a number of Air Interface Encryption algorithms are weak to key restoration assaults because the SCK/CCK community key’s an identical 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 due to this fact permits for the injection of arbitrary messages comparable to voice and knowledge.
- 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 stated the impression of the 2TETRA:2BURST depend upon the use-cases and configuration points of every specific TETRA community, and that networks that use TETRA in a data-carrying capability are notably vulnerable to packet injection assaults, doubtlessly permitting attackers to intercept radio communications and inject malicious knowledge site visitors.
“Voice replay or injection eventualities (CVE-2025-52940) may cause confusion amongst authentic customers, which can be utilized as an amplifying think about a larger-scale assault,” the corporate stated. “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 any proof of those vulnerabilities being exploited within the wild. That stated, there aren’t any patches that tackle the shortcomings, except MBPH-2025-001, for which a repair is predicted to be launched.
Mitigations for different flaws are listed beneath –
- CVE-2025-52940, CVE-2025-52942 – Migrate to scrutinized, safe E2EE answer
- CVE-2025-52941 – Migrate to non-weakened E2EE variant
- CVE-2025-52943 – Disable TEA1 assist and rotate all AIE keys
- CVE-2025-52944 – When utilizing TETRA in a knowledge carrying capability: add TLS/VPN layer on high of TETRA
“When you function or use a TETRA community, you’re actually affected by CVE-2025-52944, during which we exhibit it is potential to inject malicious site visitors right into a TETRA community, even with authentication and/or encryption enabled,” Midnight Blue stated.
“Additionally, CVE-2022-24401 seemingly impacts you, because it permits adversaries to gather keystream for both breach of confidentiality or integrity. When you function a multi-cipher community, CVE-2025-52943 poses a crucial safety threat.”
In an announcement shared with WIRED, ETSI stated the E2EE mechanism utilized in TETRA-based radios is just not a part of the ETSI commonplace, including it was produced by The Important 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 cell TETRA radios that permit attackers with bodily entry to the gadget to realize 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 as a result of architectural limitations.
“The vulnerabilities allow an attacker to achieve code execution on a Sepura Gen 3 gadget,” the corporate stated. “Assault eventualities that includes CVE-2025-8458 contain persistent code execution via entry to a tool’s SD card. Abuse of CVE-2025-52945 is much more easy because it requires solely transient entry to the gadget’s PEI connector.”
“From the premise of code execution, a number of assault eventualities are viable, comparable to 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.”
