EUVD-2025-20247

Comprehensive Technical Analysis of EUVD-2025-20247

1. Vulnerability Assessment and Severity Evaluation

The vulnerability EUVD-2025-20247, also known as CVE-2025-6811, pertains to a deserialization of untrusted data flaw in the TypeResolutionService class of Mescius ActiveReports.NET. This vulnerability allows remote attackers to execute arbitrary code on affected systems. The severity of this vulnerability is rated with a CVSS Base Score of 9.8, indicating a critical risk.

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 to exploit.
• PR:N (No Privileges Required): No privileges are required to exploit the vulnerability.
• UI:N (No User Interaction): No user interaction is required to exploit the vulnerability.
• S:U (Unchanged Scope): The vulnerability does not change the security scope.
• C:H (High Confidentiality Impact): Complete loss of confidentiality.
• I:H (High Integrity Impact): Complete loss of integrity.
• A:H (High Availability Impact): Complete loss of availability.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attacks: Given the network vector (AV:N), attackers can exploit this vulnerability remotely over the network.
• Web Applications: If the affected software is part of a web application, attackers could send malicious data through HTTP requests.
• File Uploads: If the application processes user-supplied files, an attacker could upload a specially crafted file to trigger the deserialization flaw.

Exploitation Methods:

• Crafted Payloads: Attackers can craft serialized objects that, when deserialized, execute arbitrary code.
• Man-in-the-Middle (MitM) Attacks: Intercepting and modifying network traffic to include malicious serialized data.
• Phishing: Tricking users into interacting with malicious content that exploits the vulnerability.

3. Affected Systems and Software Versions

Affected Software:

• Product: ActiveReports.NET
• Version: 18.1.1
• Vendor: Mescius

Affected Systems:

• Any system running the specified version of ActiveReports.NET.
• Systems that interact with or process data handled by ActiveReports.NET.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Patching: Apply the latest security patches provided by Mescius for ActiveReports.NET.
• Input Validation: Implement strict input validation to ensure that only trusted data is processed.
• Deserialization Controls: Use secure deserialization libraries or frameworks that validate data before deserialization.

Long-Term Mitigation:

• Code Review: Conduct thorough code reviews to identify and fix similar deserialization issues.
• Security Training: Educate developers on secure coding practices, especially regarding deserialization.
• Network Segmentation: Implement network segmentation to limit the spread of potential attacks.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations using ActiveReports.NET, particularly those in sectors where data integrity and confidentiality are critical, such as finance, healthcare, and government. The high CVSS score indicates that successful exploitation could lead to severe consequences, including data breaches, system compromises, and service disruptions.

Regulatory Compliance:

• Organizations must ensure compliance with regulations such as GDPR, which mandates robust data protection measures.
• Failure to address this vulnerability could result in regulatory penalties and loss of customer trust.

6. Technical Details for Security Professionals

Vulnerability Details:

• Class Affected: TypeResolutionService
• Root Cause: Lack of proper validation of user-supplied data leading to deserialization of untrusted data.
• Exploitation: Arbitrary code execution in the context of the current process.

Detection and Monitoring:

• Log Analysis: Monitor logs for unusual deserialization activities or unexpected code execution.
• Intrusion Detection Systems (IDS): Deploy IDS to detect and alert on suspicious network activities related to deserialization.
• Behavioral Analysis: Use behavioral analysis tools to identify anomalous behavior that may indicate an exploitation attempt.

Incident Response:

• Containment: Isolate affected systems to prevent further spread.
• Eradication: Remove malicious code and apply patches.
• Recovery: Restore systems to a known good state and validate the integrity of data.

References:

• ZDI Advisory: ZDI-25-449
• CVE Entry: CVE-2025-6811

By addressing this vulnerability promptly and comprehensively, organizations can mitigate the risk of exploitation and maintain the security and integrity of their systems.