A member of our pentest team at ProSec has, as part of his research in the area of Hardware Hacking a previously unknown vulnerability in a D-Link WLAN camera discovered – a real Zero Day with potentially far-reaching consequences. The vulnerability lies in the UART interface, which can be used to read security-relevant information such as Wi-Fi passwords and other plaintext logs, allowing conclusions to be drawn about the internal network and connected devices.
What sounds like a purely technical detail can, in the worst case, pave the way for more far-reaching network attacks – for example, when such cameras are used in unsecured corporate or home networks. Access to the camera can make it possible to intercept sensitive network data, identify nearby devices, and prepare further targeted attacks – especially if the device is integrated into the corporate network without protection. And, as his analysis shows, this can be done using the simplest of means.
In this article, we show exactly how the vulnerability works, what it means for corporate networks and private environments, and how organizations can integrate Internet of Things (IoT) devices more securely in the future.
A D-Link WLAN camera is disclosing security-critical information via its serial debug interface – including Wi-Fi access data, PINs for remote control of the device and other logged informationthat allow conclusions to be drawn about the network. The vulnerability was discovered by one of our penetration testers during a systematic hardware analysis. attacker with physical access to the device can Read network parameters, identify devices in the network and thus prepare possible attack paths.
The camera has also been frequently used in corporate contexts in the past. In poorly segmented networks or environments with IoT shadow IT, it could become a springboard for more advanced attacks. D-Link has been informed and has already responded. The award of a CVE is currently in preparation.
The discovered vulnerability affects the UART interface (Universal Asynchronous Receiver Transmitter) of the camera.
Our employee analyzed the device as part of his research and found that the serial interface extensive log data can be read – including security-relevant information such as access data and network connections. The camera communicated openly with the terminal as soon as the correct baud rate was set.
The evaluation of this interface was then successful using standard tools and minimal setup – a realistic approach even for less experienced attackers.
The Universal asynchronous receiver transmitter (UART) is a serial interface, which is used in many embedded systems – as well as in IoT devices. It is used to Communication with the device, for example for diagnostics or configuration.
In security circles, UART is considered “Backdoor for professionals“: Anyone with physical access and the necessary know-how can intervene deeply in the system via UART – as in this case.
The baud rate refers to the Transmission speed of a serial interface – that is, how many symbols are transferred between two devices per second. In practice, it usually corresponds to the number Bits per second (bps). In order for a terminal such as a PC to communicate correctly with a device such as a camera, exactly the right baud rate – otherwise only unreadable characters will appear.
Using a USB-to-serial adapter and a software terminal, our pentester was able to access internal system logs via the debug console.
Choosing the right baud rate was crucial: Only with the right settings was the communication between the camera and the terminal displayed correctly – and the sensitive log data visible.
To find this baud rate, the pentester proceeded iteratively: He tested various common baud rates until the output pattern became readable. A common approach in hardware hacking.
The extracted logs contained, among other things, Wi-Fi access data decoded in plain text using Base64, as well as a PIN indicating possible remote control of the device and other security-relevant protocols (see screenshots below). This information allows attackers to specifically use the camera as an entry point into the network and attack other systems in the vicinity.
Still without a CVE, but with a high criticality: The vulnerability was reported to D-Link and confirmed by the manufacturer. An official security advisory was published (see sources below).
The discovery was made as part of targeted hardware analyses by one of our pentestersThe aim was to Vulnerability of common IoT devices in test environments. The Wi-Fi camera in question was sourced from the consumer market to simulate real-world scenarios in which such devices are used in corporate environments – often without segmented networks, access protection, or logging.
The entire analysis process was carefully documented – from opening the camera to successfully accessing sensitive information.
Wi-Fi cameras are considered commonplace infrastructure in many organizations. However, if an attacker is able to physically tamper with such a device or if the firmware is insecure, a potential entry point into the corporate network arises:
Especially in SMEs or hybrid infrastructures (home offices, BYOD, open Wi-Fi), such devices are often not on the radar as a security risk – yet they can be a potential gateway. The result: companies are vulnerable without even knowing it.
The screenshots above show: The logs read via the serial UART interface provide security-relevant plain text data – including Base64-encoded WLAN access data, the decrypted password “hellohello”, SSID information, and references to preconfigured user IDs ("admin"). This openness in logging allows attackers to specifically analyze the device and derive attack vectors against the network.
This case provides a clear checklist for IT departments and security officers:
At ProSec, we optionally offer targeted modules for IoT security assessment, particularly as part of red teaming measures or in dedicated hardware analyses.
This case illustrates the importance of technical research in the area of hardware and IoT security – and how easily “unimportant” infrastructure can become a critical attack vector. Our employee’s work has not only led to Report to the manufacturer led, but also showed: Without in-depth security analyses, such gaps often remain undetected.
At ProSec, we help companies view their infrastructure from the perspective of a real attacker – to identify risks before they are exploited.
The vulnerability was identified in the D-Link DCS-5030L. However, similar debug interfaces exist in many other IoT devices – with comparable risks if left unprotected.
Yes – in this specific case, physical access is required, as access is via the serial interface available directly on the device. Such attacks are more common than expected in real-world scenarios – for example, through insider attackers, stolen devices, or manipulated supply chains.
Furthermore, attackers can acquire identical devices, analyze vulnerabilities, and use them to launch remote attacks – for example, via cloud features or mobile apps. Therefore, we also specifically examine physical attack vectors and the security of IoT hardware as part of our penetration tests upon request.
Many companies do not adequately secure IoT devices. For example, if If, for example, such devices are accessed as part of a physical break-in, this can serve as an entry point into the network.
Devices should be physically protected, debug interfaces disabled, and network segmentation strictly implemented. Regular penetration testing also helps identify risks early on.
The discovery has been responsibly reported to the vendor. A CVE is in preparation, and further technical details will follow as the disclosure progresses.
The warning issued by the US agency CISA regarding the vulnerability CVE-2025-9242 in WatchGuard fireware systems once again highlights the dangers of a connected world. Businesses are potentially vulnerable to attack, even without authentication. This risk impacts overall business stability and trust. A proactive approach to addressing security vulnerabilities is urgently needed.
This article highlights the strategic risks of a security vulnerability in the WordPress plugin “AI Engine” for businesses and emphasizes the need to make decisions about plugins and IT risks a top priority.
Efficiently uncover hidden attack paths in scheduled tasks. TaskHound helps! TaskHound: Search for scheduled task credentials in Windows systems and their associated information.
