EUVD-2025-24595

Comprehensive Technical Analysis of EUVD-2025-24595

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2025-24595 affects Hyland OnBase versions prior to 17.0.2.87, allowing unauthenticated remote code execution (RCE) via insecure deserialization on the .NET Remoting TCP channel. The severity of this vulnerability is rated at a Base Score of 10.0, the highest possible score under CVSS 4.0. This score reflects the critical nature of the vulnerability, which can be exploited remotely without authentication, leading to complete system compromise.

CVSS Vector Breakdown:

• AV:N (Network Vector): The vulnerability is exploitable over the network.
• AC:L (Low Complexity): The attack requires low skill or resources.
• AT:N (No Authentication): No authentication is required to exploit the vulnerability.
• PR:N (No Privileges Required): No privileges are needed to exploit the vulnerability.
• UI:N (No User Interaction): No user interaction is required to exploit the vulnerability.
• VC:H (High Confidentiality Impact): Complete confidentiality loss.
• VI:H (High Integrity Impact): Complete integrity loss.
• VA:H (High Availability Impact): Complete availability loss.
• SC:H (High Scope Change): The vulnerability affects other components beyond the initial scope.
• SI:H (High Scope Integrity): The vulnerability affects the integrity of other components.
• SA:H (High Scope Availability): The vulnerability affects the availability of other components.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector involves sending maliciously crafted data to the .NET Remoting TCP channel on port 6031, specifically targeting the TimerServer endpoint implemented in Hyland.Core.Timers.dll. The insecure deserialization of this data using the .NET BinaryFormatter allows attackers to execute arbitrary code with SYSTEM-level privileges.

Exploitation Methods:

• Network Scanning: Attackers can scan for open port 6031 to identify vulnerable systems.
• Crafted Payloads: Attackers can create payloads that exploit the insecure deserialization to achieve RCE.
• Automated Tools: Exploitation frameworks like Metasploit may develop modules to automate the exploitation process.

3. Affected Systems and Software Versions

The vulnerability affects Hyland OnBase versions prior to 17.0.2.87. Other versions may also be affected, but this has not been confirmed. Organizations using these versions are at risk and should prioritize updating to a patched version.

4. Recommended Mitigation Strategies

Immediate Actions:

• Patch Management: Upgrade to Hyland OnBase version 17.0.2.87 or later.
• Network Segmentation: Isolate systems running vulnerable versions of OnBase from the internet and internal networks.
• Firewall Rules: Block inbound and outbound traffic on port 6031 unless absolutely necessary.
• Intrusion Detection Systems (IDS): Implement IDS to monitor for suspicious activity on port 6031.

Long-Term Strategies:

• Regular Security Audits: Conduct regular security audits and vulnerability assessments.
• Code Review: Ensure that all deserialization processes use secure methods and avoid using .NET BinaryFormatter.
• User Training: Educate users on the importance of reporting suspicious activities and adhering to security policies.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations across Europe that rely on Hyland OnBase for document management and enterprise content management. Given the critical nature of the vulnerability, it could lead to widespread data breaches, system compromises, and potential disruptions in business operations. The high severity score underscores the need for immediate action to mitigate risks and protect sensitive information.

6. Technical Details for Security Professionals

Vulnerability Details:

• Endpoint: TimerServer on port 6031.
• Deserialization Mechanism: .NET BinaryFormatter.
• Privilege Level: NT AUTHORITY\SYSTEM.

Detection and Response:

• Log Analysis: Monitor logs for unusual activity on port 6031.
• Behavioral Analysis: Use behavioral analytics to detect anomalous behavior indicative of RCE attempts.
• Incident Response Plan: Develop and implement an incident response plan tailored to this vulnerability.

References:

• GitHub Gist
• Hyland OnBase Unity Client
• Hyland Support

By addressing this vulnerability promptly and comprehensively, organizations can significantly reduce the risk of exploitation and ensure the security and integrity of their systems.