CVE-2025-67114 in SCE4255W
Summary
by MITRE • 03/19/2026
Use of a deterministic credential generation algorithm in /ftl/bin/calc_f2 in Small Cell Sercomm SCE4255W (FreedomFi Englewood) firmware before DG3934v3@2308041842 allows remote attackers to derive valid administrative/root credentials from the device's MAC address, enabling authentication bypass and full device access.
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Analysis
by VulDB Data Team • 03/24/2026
The vulnerability identified as CVE-2025-67114 represents a critical security flaw in the Small Cell Sercomm SCE4255W device firmware, specifically within the /ftl/bin/calc_f2 binary component. This issue stems from the implementation of a deterministic credential generation algorithm that directly correlates administrative credentials with the device's unique MAC address. The flaw exists in firmware versions prior to DG3934v3@2308041842, making a substantial number of deployed devices susceptible to exploitation. The deterministic nature of the algorithm means that any attacker who can obtain or infer the device's MAC address can compute the corresponding administrative credentials without requiring any brute force attempts or additional attack vectors.
The technical implementation of this vulnerability involves a predictable mathematical relationship between the device's hardware identifier and the generated administrative password. The calc_f2 binary function processes the MAC address through a fixed algorithm to produce credentials that are subsequently used for device authentication. This approach violates fundamental security principles regarding credential generation, as it eliminates the randomness and unpredictability that are essential for maintaining access control. The vulnerability specifically affects the authentication mechanism of the FreedomFi Englewood deployment, where the device's MAC address serves as the sole input parameter for credential derivation. This deterministic approach creates a direct mapping between the device's physical identifier and its administrative access credentials, fundamentally undermining the security model of the device.
The operational impact of CVE-2025-67114 extends far beyond simple authentication bypass, as it provides attackers with complete administrative control over affected devices. Once an attacker determines the administrative credentials through the MAC address, they can perform any administrative function including firmware updates, configuration changes, network modifications, and access to sensitive device data. This vulnerability enables attackers to establish persistent access points within networks, potentially leading to broader security compromises including lateral movement, data exfiltration, and network infiltration. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the network perimeter, making it particularly dangerous for deployed devices that may be located in remote or unsecured environments. The impact is amplified by the fact that these devices often serve as critical infrastructure components within cellular networks, potentially affecting multiple users and network services simultaneously.
The vulnerability aligns with CWE-326 (Inadequate Encryption Strength) and CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) as it employs a predictable algorithm that fails to provide the necessary entropy for secure credential generation. From an ATT&CK framework perspective, this vulnerability maps to T1078.004 (Valid Accounts: SSH Keys) and T1566.001 (Phishing: Spearphishing Attachment) in the initial access phase, though the actual exploitation requires no user interaction. The attack pattern also corresponds to T1003.002 (OS Credential Dumping: Security Account Manager) and T1021.001 (Remote Services: Remote Desktop Protocol) in terms of privilege escalation and access exploitation. Organizations should prioritize immediate firmware updates to address this vulnerability, as the deterministic credential generation algorithm creates a permanent exposure risk. Additional mitigations include network segmentation to isolate affected devices, implementing MAC address filtering where possible, and monitoring for unauthorized access attempts. The vulnerability demonstrates the importance of avoiding deterministic credential generation in embedded systems and highlights the need for robust cryptographic practices in device authentication mechanisms.
This vulnerability represents a significant weakness in the security architecture of the affected devices and underscores the critical importance of proper credential management in networked embedded systems. The deterministic approach to credential generation, while potentially simplifying device management for legitimate users, creates an exploitable weakness that fundamentally compromises the security posture. The remote attack surface and the complete administrative access granted make this vulnerability particularly dangerous for network infrastructure devices. Security practitioners should consider this vulnerability as part of broader network security assessments and ensure that all similar devices in their environment are evaluated for similar deterministic credential generation flaws. The incident highlights the need for comprehensive security testing of embedded firmware components and the importance of implementing randomized credential generation algorithms that meet industry standards for cryptographic security.