CVE-2022-24400 in Derived Cypher Key (Tetraburst)
Summary
by MITRE • 10/25/2023
A flaw in the TETRA authentication procecure allows a MITM adversary that can predict the MS challenge RAND2 to set session key DCK to zero.
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Analysis
by VulDB Data Team • 11/11/2023
The vulnerability identified as CVE-2022-24400 resides within the TETRA (Terrestrial Trunked Radio) authentication procedure, a critical component of telecommunications security protocols used primarily in public safety and government communications systems. This flaw represents a significant weakness in the cryptographic framework that governs how devices authenticate with TETRA networks, potentially compromising the integrity of secure communications channels. The vulnerability specifically targets the challenge-response mechanism that establishes session keys for encrypted communication between mobile stations and network infrastructure.
The technical implementation of this vulnerability stems from a predictable challenge sequence within the TETRA authentication protocol where adversaries can anticipate the MS challenge RAND2 values. This predictability arises from insufficient randomness or cryptographic weakness in the challenge generation process, allowing malicious actors to compute or guess the challenge values that should remain unpredictable. When an attacker successfully predicts RAND2, they can manipulate the authentication process to force the session key DCK to be set to zero, effectively nullifying the cryptographic protection that should secure the communication session.
The operational impact of this vulnerability extends beyond simple cryptographic weakness, as it fundamentally undermines the security model of TETRA networks where authentication and encryption are tightly coupled. An adversary who successfully exploits this vulnerability can establish unauthorized communication sessions with TETRA devices, potentially gaining access to sensitive government or public safety communications. This capability enables passive monitoring of encrypted traffic, active interception of communications, and potential manipulation of network operations. The attack vector requires only the ability to perform man-in-the-middle positioning and predict challenge values, making it particularly dangerous as it can be executed without requiring sophisticated cryptographic attacks or extensive computational resources.
This vulnerability aligns with CWE-330, which addresses the use of insufficiently random values in security contexts, and represents a specific implementation flaw in the cryptographic protocol that violates fundamental security principles. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under the T1566 category for credential access through network sniffing and man-in-the-middle attacks. The exploitation of this vulnerability requires minimal skill levels and can be automated, making it particularly concerning for critical infrastructure protection. Organizations implementing TETRA systems must consider the potential for unauthorized access to sensitive communications, especially in environments where public safety or national security operations are conducted.
Mitigation strategies for CVE-2022-24400 should focus on immediate protocol updates to strengthen the challenge generation mechanisms and implement proper random number generation for challenge values. Network administrators should conduct comprehensive security assessments of their TETRA infrastructure to identify potentially affected systems and implement cryptographic patches or protocol modifications. The vulnerability highlights the importance of robust randomness in security protocols and underscores the need for regular cryptographic audits of telecommunications systems. Organizations should also consider implementing additional monitoring mechanisms to detect anomalous authentication patterns that might indicate exploitation attempts, while ensuring that all TETRA network components are updated to versions that address this specific cryptographic weakness.