CVE-2023-45878

Comprehensive Technical Analysis of CVE-2023-45878

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2023-45878

Description: GibbonEdu Gibbon version 25.0.1 and earlier contains a vulnerability that allows for Arbitrary File Write due to the lack of authentication in the rubrics_visualise_saveAjax.phps endpoint. This endpoint accepts img, path, and gibbonPersonID parameters, where the img parameter is expected to be a base64 encoded image. If the path parameter is set, the defined path is used as the destination folder, concatenated with the absolute path of the installation directory. The content of the img parameter is base64 decoded and written to the defined file path. This allows the creation of PHP files that permit Remote Code Execution (RCE) without authentication.

CVSS Score: 9.8

Severity Evaluation: The CVSS score of 9.8 indicates a critical vulnerability. This high score is due to the potential for unauthenticated RCE, which can lead to full system compromise. The lack of authentication and the ability to write arbitrary files make this vulnerability particularly dangerous.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

1. Unauthenticated Access: An attacker can exploit this vulnerability without needing any credentials, making it highly accessible.
2. Arbitrary File Write: The attacker can write any file to any directory within the installation path, including executable PHP files.
3. Remote Code Execution: By writing a PHP file with malicious code, the attacker can execute arbitrary commands on the server.

Exploitation Methods:

1. Base64 Encoded Payload: The attacker can encode a malicious PHP script in base64 and send it via the img parameter.
2. Path Manipulation: The attacker can specify a path to a critical directory (e.g., the web root) to place the malicious file.
3. Execution: Once the file is written, the attacker can trigger its execution by accessing it through the web server.

3. Affected Systems and Software Versions

Affected Software:

• GibbonEdu Gibbon version 25.0.1 and earlier.

Affected Systems:

• Any server running the affected versions of GibbonEdu Gibbon.
• Systems where the rubrics_visualise_saveAjax.phps endpoint is accessible without proper authentication.

4. Recommended Mitigation Strategies

Immediate Actions:

1. Patching: Upgrade to a version of GibbonEdu Gibbon that addresses this vulnerability.
2. Access Control: Implement strict access controls to ensure that only authenticated users can access sensitive endpoints.
3. Input Validation: Validate and sanitize all input parameters, especially those that can influence file operations.
4. File Permissions: Restrict file write permissions to only necessary directories and ensure that executable files cannot be written to sensitive locations.

Long-Term Strategies:

1. Regular Updates: Ensure that all software is regularly updated to the latest versions.
2. Security Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate potential risks.
3. Monitoring: Implement monitoring and logging to detect and respond to suspicious activities.

5. Impact on Cybersecurity Landscape

Immediate Impact:

• Organizations using the affected versions of GibbonEdu Gibbon are at high risk of unauthenticated RCE, which can lead to data breaches, system compromise, and other severe security incidents.

Long-Term Impact:

• This vulnerability highlights the importance of robust authentication and input validation mechanisms.
• It underscores the need for continuous monitoring and prompt patching of software vulnerabilities.
• The cybersecurity community may see an increase in similar vulnerabilities being exploited, prompting a renewed focus on secure coding practices.

6. Technical Details for Security Professionals

Vulnerability Details:

• Endpoint: rubrics_visualise_saveAjax.phps
• Parameters: img, path, gibbonPersonID
• Exploitation: The img parameter is base64 decoded and written to the specified path. The lack of authentication allows unauthorized file writes.

Detection:

• Log Analysis: Look for unusual file write operations and access to the rubrics_visualise_saveAjax.phps endpoint.
• File Integrity Monitoring: Monitor for unexpected changes in critical directories.

Mitigation:

• Code Review: Ensure that all file operations are authenticated and that input parameters are properly validated.
• Web Application Firewall (WAF): Implement a WAF to block suspicious requests to the vulnerable endpoint.

References:

• USD Security Advisory

By addressing this vulnerability promptly and implementing robust security measures, organizations can significantly reduce the risk of exploitation and protect their systems from potential attacks.