EUVD-2023-27707

Comprehensive Technical Analysis of EUVD-2023-27707

1. Vulnerability Assessment and Severity Evaluation

The vulnerability described in EUVD-2023-27707 pertains to an unrestricted file upload flaw in the erohtar/Dasherr dashboard for self-hosted services. This vulnerability allows unauthenticated users to execute arbitrary code on the server by uploading malicious files. The severity of this vulnerability is rated with a CVSS Base Score of 9.8, which is considered critical. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H indicates the following:

• Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
• Attack Complexity (AC): Low (L) - The attack requires minimal skill or resources.
• Privileges Required (PR): None (N) - No authentication is required to exploit the vulnerability.
• User Interaction (UI): None (N) - No user interaction is required.
• Scope (S): Unchanged (U) - The vulnerability does not change the security scope.
• Confidentiality (C): High (H) - The vulnerability allows for unauthorized access to sensitive information.
• Integrity (I): High (H) - The vulnerability allows for unauthorized modification of data.
• Availability (A): High (H) - The vulnerability allows for disruption of service.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector is the unrestricted file upload functionality in the /www/include/filesave.php script. An attacker can exploit this vulnerability by:

1. Uploading a Malicious PHP File: The attacker can upload a PHP file containing malicious code to the server.
2. Executing Arbitrary Code: Once the file is uploaded, the attacker can execute the malicious code by accessing the uploaded file via a web browser.
3. Gaining Control: The executed code can perform various malicious activities, such as data exfiltration, unauthorized access, or further exploitation of the server.

3. Affected Systems and Software Versions

The vulnerability affects all versions of erohtar/Dasherr prior to version 1.05.00. Users running any version below 1.05.00 are at risk and should upgrade immediately.

4. Recommended Mitigation Strategies

1. Upgrade to the Latest Version: Users should upgrade to Dasherr version 1.05.00 or later, which addresses the vulnerability.
2. Implement File Upload Restrictions: Ensure that file uploads are restricted to specific file types and locations.
3. Regular Security Audits: Conduct regular security audits and code reviews to identify and mitigate similar vulnerabilities.
4. Monitoring and Logging: Implement robust monitoring and logging mechanisms to detect and respond to suspicious activities.
5. Network Segmentation: Segment the network to limit the potential impact of a successful exploit.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to organizations using Dasherr for self-hosted services within the European Union. Given the critical nature of the vulnerability, it could lead to data breaches, unauthorized access, and service disruptions. Organizations must prioritize patching and implementing robust security measures to mitigate the risk.

6. Technical Details for Security Professionals

• Vulnerable Component: The file /www/include/filesave.php allows for unrestricted file uploads.
• Exploitation Steps:
  1. Craft a malicious PHP file with arbitrary code.
  2. Upload the file using the vulnerable endpoint.
  3. Access the uploaded file via a web browser to execute the code.
• Detection:
  • Monitor for unusual file upload activities.
  • Implement file integrity monitoring to detect unauthorized changes.
• Response:
  • Immediately upgrade to the patched version.
  • Review and audit file upload functionalities.
  • Implement additional security controls to prevent similar vulnerabilities.

Conclusion

EUVD-2023-27707 highlights a critical vulnerability in erohtar/Dasherr that requires immediate attention. Organizations should prioritize upgrading to the latest version and implementing additional security measures to protect against potential exploits. The European cybersecurity landscape must remain vigilant against such vulnerabilities to ensure the integrity and security of digital infrastructure.