Vulnerable Gladinet Servers Enable Remote Code Execution

Key Takeaways

• CentreStack and Triofox are vulnerable to remote code execution, which can lead to malware deployment, backdoor persistence, and credential theft.
• The vulnerability is caused by a design failure in the generation of cryptographic keys used to encrypt access tokens.
• The "GenerateSecKey()" function returns the same static 100-byte strings every time the service runs, allowing attackers to extract and use the keys to decrypt any ticket generated by the server.
• Huntress has urged all CentreStack/Triofox customers to update to the latest version, 16.12.10420.56791, to mitigate the vulnerability.
• Nine of Huntress’ enterprise customers have already been affected by the vulnerability.

Introduction to the Vulnerability
As with any internet-facing server, remote code execution on CentreStack or Triofox can have severe consequences, including malware deployment, backdoor persistence, and credential theft. Recently, Huntress, a cybersecurity firm, discovered a critical vulnerability in CentreStack and Triofox, two popular file-sharing platforms. The vulnerability allows attackers to execute arbitrary code on the server, which can lead to a range of malicious activities. Huntress has urged all CentreStack/Triofox customers to update to the latest version, 16.12.10420.56791, to mitigate the vulnerability. Unfortunately, nine of Huntress’ enterprise customers have already been affected by the vulnerability, highlighting the importance of prompt action.

The Root Cause of the Issue
At the core of the issue is a design failure in how CentreStack and Triofox generate the cryptographic keys used to encrypt the access tokens the platforms use to control who can retrieve what files. The server relies on a function called "GenerateSecKey()" to produce the AES key and initialization vector (IV) for ticket encryption. However, instead of generating unique values, the function returns the same static 100-byte strings every time the service runs. This means that the keys never change, making it possible for attackers to extract them from memory once and use them to decrypt any ticket generated by the server or even encrypt their own malicious tickets.

Consequences of the Vulnerability
The consequences of this vulnerability are severe. Because the keys never change, an attacker can extract them from memory once and use them to decrypt any ticket generated by the server or worse, encrypt their own. This allows the attacker to gain unauthorized access to sensitive files and data, potentially leading to data breaches, intellectual property theft, and other malicious activities. Furthermore, the static nature of the keys means that an attacker can use them to create their own tickets, allowing them to move laterally within the network and gain access to additional resources. The fact that the keys are static strings of Chinese and Japanese text makes it even easier for attackers to identify and exploit them.

Mitigation and Recommendations
To mitigate the vulnerability, Huntress has urged all CentreStack/Triofox customers to update to the latest version, 16.12.10420.56791. This update addresses the design flaw in the "GenerateSecKey()" function and ensures that unique cryptographic keys are generated for each session. It is essential for customers to apply this update as soon as possible to prevent potential attacks. Additionally, customers should monitor their systems for any suspicious activity and implement additional security measures, such as multi-factor authentication and intrusion detection systems, to prevent and detect potential attacks.

Conclusion and Future Directions
In conclusion, the vulnerability in CentreStack and Triofox highlights the importance of robust security design and testing in software development. The use of static cryptographic keys is a critical design flaw that can have severe consequences, including remote code execution, malware deployment, and credential theft. As software vendors, it is essential to prioritize security and implement robust testing and validation procedures to identify and address potential vulnerabilities before they can be exploited. By doing so, we can prevent attacks and protect sensitive data and systems from malicious activities.