CVE-2022-24401 in Air Interface Encryption (Tetraburst)
Summary
by MITRE • 10/25/2023
Adversary-induced keystream re-use on TETRA air-interface encrypted traffic using any TEA keystream generator. IV generation is based upon several TDMA frame counters, which are frequently broadcast by the infrastructure in an unauthenticated manner. An active adversary can manipulate the view of these counters in a mobile station, provoking keystream re-use. By sending crafted messages to the MS and analyzing MS responses, keystream for arbitrary frames can be recovered.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/11/2023
The vulnerability described in CVE-2022-24401 represents a critical cryptographic weakness in the TETRA air-interface communication protocol that affects the confidentiality of encrypted traffic. This issue stems from the implementation of the TEA (Tiny Encryption Algorithm) keystream generator within the TETRA framework, where the initialization vector generation relies on TDMA frame counters that are transmitted through the network infrastructure. The fundamental flaw lies in the lack of authentication for these frame counter values, which are broadcast in an unauthenticated manner by the network infrastructure components. This design oversight creates an exploitable condition where malicious actors can manipulate the frame counter values observed by mobile stations, leading to predictable cryptographic failures.
The technical exploitation of this vulnerability occurs through active man-in-the-middle attacks that specifically target the frame counter synchronization mechanism within TETRA networks. An adversary positioned to intercept and modify network traffic can manipulate the TDMA frame counter values that mobile stations receive, causing the TEA keystream generator to produce identical keystreams for different frames. This keystream re-use directly violates the core principles of cryptographic security, as the same keystream is applied to multiple data payloads, enabling attackers to perform cryptographic attacks such as crib-dragging or differential cryptanalysis. The attack methodology involves sending carefully crafted messages to mobile stations and analyzing the responses to reconstruct keystream values for arbitrary frames, effectively breaking the encryption scheme.
The operational impact of this vulnerability extends beyond simple data confidentiality breaches, as it fundamentally compromises the security model of TETRA networks used primarily in public safety and government communications. Mobile stations within affected networks become vulnerable to traffic analysis attacks, where adversaries can correlate communications patterns and potentially extract sensitive information from encrypted payloads. The vulnerability affects the integrity of the encryption process by undermining the randomness and uniqueness properties that cryptographic systems depend upon for security. According to CWE-327, this represents a weakness in a cryptographic algorithm that allows for predictable or repeatable keystream generation, while the attack pattern aligns with ATT&CK technique T1559.001 for implementing cryptographic attacks against network protocols. Organizations relying on TETRA infrastructure for critical communications face potential exposure of operational details, strategic information, and sensitive personal data that would normally be protected by encryption.
Mitigation strategies for this vulnerability require immediate implementation of authentication mechanisms for frame counter values transmitted within the TETRA network infrastructure. Network administrators must deploy cryptographic integrity protection for TDMA frame counter broadcasts to prevent adversarial manipulation of these critical synchronization values. The solution involves implementing authenticated frame counter updates that validate the source and integrity of counter information before acceptance by mobile stations. Additionally, network operators should consider implementing cryptographic key rotation mechanisms that can detect and respond to keystream re-use conditions, as outlined in NIST SP 800-57 guidelines for cryptographic key management. The implementation of these mitigations requires careful coordination between network infrastructure vendors and operators to ensure proper authentication mechanisms are deployed without disrupting existing communications services. Organizations should also conduct comprehensive security assessments of their TETRA network configurations to identify potential exposure points and implement monitoring solutions that can detect anomalous frame counter behavior patterns.