CVE-2026-77960 in ELD
Summary
by MITRE • 09/18/2026
Bransys ELD is shipped with hardcoded MQTT credentials, which will grant read access to real-time data for every active device across a subset of carriers that were connected to the affected MQTT broker.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in Bransys Electronic Logging Device (ELD) systems involves the presence of hardcoded Message Queuing Telemetry Transport (MQTT) credentials within the software distribution. This configuration flaw allows any entity with network access to the specific MQTT broker used by these devices to authenticate using static, unchanging username and password pairs that are embedded directly into the application code or firmware rather than being dynamically generated or securely stored per device instance. Because these credentials remain constant across all units shipped for a subset of carriers connected to this particular broker, they serve as a universal key that bypasses individual authentication mechanisms intended to restrict data access. This represents a fundamental failure in secure credential management and identity verification protocols within the Internet of Things (IoT) ecosystem, where device-specific secrets are critical for maintaining isolation between different users or organizations sharing infrastructure.
From a technical perspective, this issue aligns with CWE-798: Use of Hard-coded Credentials, which describes the use of static authentication data that is not unique to each instance and cannot be changed by administrators without updating the software itself. The operational impact is severe because MQTT brokers often facilitate real-time telemetry streaming from connected hardware devices such as ELDs in commercial vehicles. By leveraging these hardcoded credentials, an attacker can subscribe to relevant topics on the broker to receive live data streams for every active device linked to that specific carrier network. This includes sensitive information regarding driver hours of service, location tracking, vehicle diagnostics, and potentially other proprietary operational metrics. The scope of exposure is limited only by the number of devices currently connected to the affected MQTT endpoint at any given time, creating a significant privacy risk for drivers and a competitive intelligence risk for carriers who rely on this data for logistics optimization and regulatory compliance reporting.
The exploitation of this vulnerability does not require complex reverse engineering or zero-day exploits; it relies primarily on network reconnaissance and basic authentication against known default credentials. An attacker would first need to discover the IP address or domain name of the MQTT broker, which may be exposed via DNS records or service discovery protocols if proper network segmentation is absent. Once the endpoint is identified, standard MQTT client tools can be used to attempt login with the hardcoded username and password pair. Upon successful authentication, the attacker gains read-only access to a continuous stream of real-time data from multiple vehicles simultaneously. This capability enables mass surveillance capabilities that were not intended by the system designers, violating the principle of least privilege and failing to ensure confidentiality for end-users whose personal movement patterns are being broadcasted over potentially unencrypted or weakly secured channels depending on additional TLS configurations which may also be misconfigured in such environments.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. In the short term, Bransys should issue a software update that replaces hardcoded credentials with dynamic authentication methods, such as per-device certificates or unique tokens generated during provisioning. Carriers utilizing this system should immediately change any configurable passwords if possible and isolate their MQTT brokers from public-facing networks using firewalls to restrict access only to authorized IP ranges associated with the Bransys infrastructure. Long-term solutions involve implementing mutual TLS (mTLS) authentication where both client and server verify each other's identities, ensuring that even if credentials are leaked, they cannot be reused by unauthorized parties without possessing valid certificates signed by a trusted authority. Additionally, adopting industry standards such as NIST SP 800-193 for platform firmware resiliency can help ensure that devices maintain secure states and resist tampering with authentication mechanisms throughout their lifecycle.
This vulnerability also maps to MITRE ATT&CK techniques related to Initial Access and Credential Access, specifically T1078: Valid Accounts, where attackers use legitimate credentials found in the environment or hardcoded into software to gain initial foothold. Furthermore, it relates to T1539: Steal Web Session Token if session hijacking is possible via MQTT sessions, though primarily this case involves direct data exfiltration through subscription topics rather than session theft. The lack of unique per-device identity management highlights a broader industry challenge in IoT security where convenience and ease of deployment often override robustness of authentication systems. Organizations must prioritize secure by design principles during development phases to prevent such systemic weaknesses that compromise the integrity and privacy of large fleets of connected devices simultaneously. Regular penetration testing focused on default credential checks and MQTT broker hardening should be integrated into the security assessment lifecycle for any IoT-dependent enterprise infrastructure.