CVE-2026-24479

Comprehensive Technical Analysis of CVE-2026-24479

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2026-24479

Description: HUSTOF, an open-source online judge system based on PHP/C++/MySQL/Linux, is vulnerable to a path traversal issue in its problem_import_qduoj.php and problem_import_hoj.php modules. This vulnerability allows attackers to upload malicious ZIP files containing files with path traversal sequences, leading to Remote Code Execution (RCE).

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 complete system compromise, including the execution of arbitrary code on the server. The vulnerability can be exploited remotely without any user interaction, making it highly dangerous.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Malicious ZIP File Upload: An attacker can craft a ZIP file containing files with path traversal sequences (e.g., ../../shell.php). When this ZIP file is uploaded and extracted by the server, it can write files to arbitrary locations within the web root.
• Remote Code Execution (RCE): By placing a malicious PHP script within the ZIP file, an attacker can execute arbitrary code on the server, leading to full control over the system.

Exploitation Methods:

• Path Traversal: The attacker exploits the lack of proper filename sanitization to traverse directories and place files in unintended locations.
• Code Injection: Once the malicious file is placed in the web root, the attacker can access it via a web browser or automated script to execute the injected code.

3. Affected Systems and Software Versions

Affected Systems:

• HUSTOF versions prior to 26.01.24

Software Versions:

• All versions of HUSTOF before the patch released in version 26.01.24 are vulnerable.

4. Recommended Mitigation Strategies

Immediate Actions:

• Update to the Latest Version: Upgrade to HUSTOF version 26.01.24 or later, which includes the fix for this vulnerability.
• Temporary Mitigation: If an immediate update is not possible, disable the problem_import_qduoj.php and problem_import_hoj.php modules to prevent malicious uploads.

Long-Term Strategies:

• Input Validation: Implement robust input validation and sanitization for all file uploads to prevent path traversal attacks.
• Regular Security Audits: Conduct regular security audits and code reviews to identify and mitigate similar vulnerabilities.
• Monitoring and Logging: Enhance monitoring and logging to detect and respond to suspicious activities related to file uploads and extraction processes.

5. Impact on Cybersecurity Landscape

Implications:

• Widespread Adoption: Given the popularity of HUSTOF in educational and competitive programming environments, this vulnerability poses a significant risk to numerous institutions and organizations.
• Exploitation Potential: The ease of exploitation and the critical nature of the vulnerability make it a prime target for attackers, potentially leading to widespread compromises.
• Reputation and Trust: Organizations using vulnerable versions of HUSTOF may face reputational damage and loss of trust if exploited.

6. Technical Details for Security Professionals

Vulnerability Details:

• Root Cause: The vulnerability stems from insufficient sanitization of filenames within uploaded ZIP archives, allowing path traversal sequences to be included.
• Exploitation Steps:
  1. Craft a ZIP file containing a file with a path traversal sequence (e.g., ../../shell.php).
  2. Upload the ZIP file via the vulnerable modules (problem_import_qduoj.php or problem_import_hoj.php).
  3. The server extracts the ZIP file, placing the malicious file in the web root.
  4. Access the malicious file via a web browser to execute arbitrary code.

Detection and Response:

• Detection: Implement file integrity monitoring (FIM) to detect unauthorized file modifications in the web root.
• Response: In case of detection, immediately isolate the affected server, investigate the incident, and apply the necessary patches or updates.

References:

• Patch Commit
• Vendor Advisory

By addressing this vulnerability promptly and implementing robust security measures, organizations can mitigate the risk of exploitation and ensure the integrity and security of their systems.