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Telecom / Consumer IoT

Hardware Security Assessment of a 4G Dongle for a Giant Telecom Company

A 7-decade-old UK telecom manufacturer needed to know whether its 4G dongle could withstand real-world attacks before mass rollout. Payatu ran a full hardware, firmware, protocol and web application assessment, then validated every fix through a dedicated retesting round.

Hardware Security Assessment, Firmware Security Assessment, Web Application Security Testing

At a glance

INDUSTRY

Telecom / Consumer IoT

CLIENT PROFILE

7-decade-old UK-based telecom manufacturer of consumer electronics and IoT devices

SERVICES

Hardware Security Assessment, Firmware Security Assessment, Web Application Security Testing

ENGAGEMENT

Hardware, firmware and web application assessment of a 4G dongle

key Numbers

16

Vulnerability Findings

3

Attack Surfaces Assessed (Hardware, Firmware, Web Application)

18

Remediation Recommendations Delivered

Key Takeaways

Client – A 7-decade-old UK-based telecommunications company that manufactures consumer electronics and IoT devices.

Problem – The client needed to assess the cyber resilience of its 4G dongle and its web application before mass rollout, given rising incidents of attackers using IoT devices to infiltrate larger networks.

What Payatu did – We ran a 4-phase hardware, firmware, protocol and web application assessment covering debug port exposure, memory extraction, access control, authentication and input validation, followed by validation and retesting of fixes.

Outcome – We delivered 18 remediation recommendations covering JTAG and UART hardening, firmware encryption, access control and input validation, giving the client a clear path to closing the gaps before the device reached consumers.

the challenge

Why the client called us in

IoT devices have become a favored entry point for attackers looking to pivot into larger corporate networks, and a 7-decade-old UK telecom manufacturer wanted to make sure its 4G dongle wasn't one of them. With the device headed for mass consumer rollout, any undetected vulnerability in its hardware, firmware or companion web application could translate into a large-scale cyber event, reputational damage and direct financial loss. The client brought in Payatu to assess the dongle end to end before it reached the market.
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Determine whether hardware debug ports could be abused to extract memory or firmware
Verify access control and authentication across the device and its web application
Confirm user input was properly escaped and validated

scope of engagement

What was in scope

Hardware assessment of the 4G dongle, including debug ports such as UART and JTAG
Firmware assessment for hardcoded credentials, insecure protocols, outdated libraries and improper input validation
Web application assessment of the device's companion application
Protocol assessment covering communication channels and susceptibility to MITM and DoS attacks
Access control and authentication testing across device and application functions

Our Approach

How Payatu ran the engagement

01

Initial Recon

We gathered available information on the device, including an FCC ID search and analysis of the radio protocols in use.

02

External Inspection

We examined the device's physical build, including button functions, external interfaces such as Ethernet and USB, screw types and tamper-protection mechanisms.

03

Reporting and Documentation

We documented every finding, the exploitation technique used, its impact and clear remediation guidance.

04

Validation and Retesting

We worked with the device owner to validate fixes and retested to confirm the vulnerabilities were effectively addressed.

Key findings

What we found

Hardware Debug Interfaces

JTAG pins were exposed on the PCB and the UART port allowed shell and root access with debug messages left enabled, giving an attacker with physical access a direct path into the device.

Firmware Security

The firmware used outdated libraries and binaries and was not adequately encrypted or compressed, and an NV binary containing device configuration data was left on the device.

Access Control

Several device functions, including creating, deleting and checking for the existence of directories and files, required no authentication before executing.

Input Validation

User input was not properly sanitized before being used to build system commands or SMS payloads, and uploaded files were not validated against a type whitelist.

the outcome

Results and Impact

The assessment gave the client a complete view of the 4G dongle's attack surface across hardware, firmware, protocol and web layers, despite a compressed timeline and a scope that expanded midway through the engagement. Every finding came with a specific fix, and Payatu validated the remediations through a dedicated retesting round before the device moved forward.

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