Code Injection in EyouCMS Template File Handler

Executive Summary

This vulnerability exists in EyouCMS up to version 1.7.9, specifically in the editFile function of the file application/admin/logic/FilemanagerLogic.php within the Template File Handler component.

An attacker can remotely manipulate this function to inject malicious code, potentially compromising the system.

The vulnerability has been publicly disclosed and an exploit is available, but the project maintainers have not yet responded to the issue.

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Detection Guidance

This vulnerability can be detected by checking for the presence of malicious ThinkPHP template tags {:system('command')} or similar {:function()} tags injected into template files managed by EyouCMS, especially in the backend file manager.

Since exploitation requires authenticated admin access to edit template files, detection involves auditing template files for suspicious {:} tags that could lead to code execution.

Suggested commands include searching for the {:} tags in template files on the server, for example:

• grep -r "{:system(" /path/to/eyoucms/templates/
• grep -r "{:" /path/to/eyoucms/templates/ | grep -v "safe_tags"

Additionally, monitoring web server logs for unusual requests to the admin panel's template editing interface or unexpected frontend page requests that trigger code execution can help detect exploitation attempts.

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Impact Analysis

This vulnerability allows remote attackers to inject code into the affected system, which can lead to unauthorized code execution.

Such code injection can compromise the integrity and security of the system, potentially allowing attackers to gain control, manipulate data, or disrupt services.

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Compliance Impact

The vulnerability allows an authenticated admin to perform remote code execution by injecting malicious code into template files, potentially leading to full server compromise.

Such a compromise could result in unauthorized access to sensitive data, disruption of services, and loss of data integrity, which may violate requirements of common standards and regulations like GDPR and HIPAA that mandate protection of personal and sensitive information.

However, the provided information does not explicitly state the direct impact on compliance with these standards.

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Mitigation Strategies

Immediate mitigation steps include restricting and monitoring admin panel access to trusted users only, as exploitation requires authenticated admin privileges.

Audit and remove any suspicious {:} template tags from template files to prevent code injection.

If possible, disable or restrict the template editing functionality in the admin panel until a patch or official fix is released.

Implement strict input validation and sanitization on template file edits to block the injection of ThinkPHP native tags like {:system()}.

Monitor server logs for unusual activity and consider isolating or taking offline affected systems to prevent further exploitation.

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