CVE-2023-4258 in Zephyr
Summary
by MITRE • 09/26/2023
In Bluetooth mesh implementation If provisionee has a public key that is sent OOB then during provisioning it can be sent back and will be accepted by provisionee.
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Analysis
by VulDB Data Team • 10/16/2023
The vulnerability described in CVE-2023-4258 resides within the Bluetooth mesh network provisioning process, specifically affecting the security mechanisms that govern device authentication and key exchange. This flaw impacts the provisionee component of Bluetooth mesh networks which serves as the device being configured or provisioned by another device known as the provisioner. The vulnerability stems from improper validation of public key materials during the out-of-band provisioning phase where cryptographic keys are exchanged between devices to establish secure communication channels within the mesh network.
The technical implementation flaw occurs when a provisionee receives a public key through out-of-band means during the provisioning process and subsequently accepts this key without proper verification of its authenticity or integrity. This represents a critical breakdown in the cryptographic validation procedures that should ensure only legitimate keys are accepted during the mesh network establishment phase. The vulnerability allows an attacker to potentially inject malicious public keys into the provisioning process, thereby compromising the security of the entire mesh network that the provisionee participates in.
From an operational impact perspective, this vulnerability undermines the fundamental security guarantees that Bluetooth mesh networks are designed to provide. The ability to inject forged public keys during provisioning enables attackers to potentially perform man-in-the-middle attacks against mesh network communications, compromise device authentication mechanisms, and gain unauthorized access to network resources. This flaw particularly affects the integrity of the mesh network topology and can lead to widespread security breaches across all devices within the compromised network segment. The vulnerability is especially concerning in environments where Bluetooth mesh networks are used for critical infrastructure management, industrial automation, or security systems where network integrity is paramount.
The vulnerability aligns with CWE-310, which addresses cryptographic weaknesses in key management and validation processes. It also maps to ATT&CK technique T1552.001, which covers unsecured credentials and key material exposure during network communication processes. Organizations implementing Bluetooth mesh networks should implement immediate mitigations including enhanced key validation procedures, regular security audits of mesh network configurations, and deployment of updated firmware versions that address the specific key acceptance flaw. Additionally, network administrators should consider implementing network segmentation and monitoring mechanisms to detect anomalous provisioning activities that might indicate exploitation attempts. The recommended approach involves strengthening the cryptographic validation routines within the provisionee implementation to ensure that all received public keys undergo rigorous authentication checks before being accepted into the mesh network configuration process, thereby maintaining the integrity of the Bluetooth mesh security framework and protecting against unauthorized device inclusion in secure network topologies.