CVE-2023-50917: MajorDoMo RCE Lets Hackers Control Your Lights, Cameras, Everything
Imagine a world where your home intelligently adapts to your needs, where comfort and convenience are just a voice command away. This is the promise of MajorDoMo (Major Domestic Module), an open-source smarthome automation platform that has captivated DIY enthusiasts. Its allure lies in its flexibility and compatibility with various protocols and services, easily deployed on any modern device running Windows or Linux OS. Employing web technologies and the principles of Object-Oriented Programming, MajorDoMo offers an unparalleled level of customization for automation rules and scripts. However, a critical vulnerability looms over this innovative platform.
Image: Majordomohome
Beneath the user-friendly facade of MajorDoMo’s thumb.php module lies a severe vulnerability, unauthenticated Remote Code Execution (RCE), ominously tagged as CVE-2023-50917 and scoring a 9.8 on the CVSS scale. The heart of this vulnerability is the unchecked and unsanitized user input from the transport parameter, which is directly executed as a system command. This glaring oversight opens the floodgates for attackers to execute arbitrary commands on the server, potentially seizing full control of the MajorDoMo instance.
Researchers, including Chocapikk, have unveiled the technical intricacies of this flaw. Two primary exploitation methods have emerged:
1. Bypassing URL Validation: The initial guard of the script checks for URL patterns like rtsp: or /dev. However, this check crumbles under the clever use of base64 encoded strings, such as “cnRzcDovL2EK” (which decodes to rtsp://a), rendering the validation ineffective.
2. Command Injection via the transport Parameter: With no sanitization mechanism, the transport parameter becomes a Trojan horse. Attackers exploit it to inject commands, leading to RCE. For instance, appending ||echo; echo $(command_here) to a command breaks the intended execution flow, enabling the execution of any arbitrary command.
The implications of the CVE-2023-50917 vulnerability are far-reaching and deeply concerning. Given MajorDoMo’s central role in home automation, a successful exploitation could breach the sanctity of your home. Attackers could compromise physical security systems, gain unauthorized access to surveillance cameras, and even hijack other connected IoT devices, turning your smart home into a puppet.
The discovery of CVE-2023-50917 serves as a stark reminder of the importance of cybersecurity in the realm of smart home automation. To shield against such vulnerabilities, users and developers are urged to take the following steps:
– Thorough Input Validation: Implementing rigorous input validation can act as the first line of defense against malicious payloads.
– Sanitize Before Execution: Sanitizing inputs before integrating them into system commands is crucial to prevent exploitation.
– Limit Direct Command Execution: Instead of directly executing system commands, the use of built-in PHP functions or secure APIs is recommended to mitigate risks.
