A recently discovered vulnerability, CVE-2023-2059, has been identified in the popular web content management system, DedeCMS 5.7.87. This vulnerability has been rated problematic, as it could lead to potential unauthorized access and manipulation of sensitive data on the affected system. In this long read post, we will explain the details of this vulnerability, provide code snippets and original references, and discuss how to mitigate the risk associated with this exploit.

Vulnerability Details

The CVE-2023-2059 vulnerability affects an unknown functionality of the file uploads/include/dialog/select_templets.php in DedeCMS 5.7.87. The issue arises when a malicious user manipulates the system through a path traversal attack, using the ..\filedir pattern to access unauthorized directories on the targeted system. Since this attack can be launched remotely, it poses a significant threat to the confidentiality, integrity, and availability of the affected system.

Exploit Database Reference: VDB-225944

Code Snippet

The following code snippet demonstrates the vulnerable parameter and the manipulation performed by an attacker:

<?php
$cfg_basedir = '..\filedir'; // Vulnerable parameter
if(!isset($activepath)) $activepath='';
$activepath = str_replace('.','',$activepath);
$activepath = preg_replace("/[^\/()-1-_]/", '', $activepath);
$cfg_templeturl = valueOf($activepath.url, "templeturl");
?>

In the example above, the $cfg_basedir variable is susceptible to path traversal, as it can be modified by an attacker by injecting the ..\filedir pattern.

Exploit Steps

1. An attacker crafts a malicious URL with the path traversal payload, targeting the uploads/include/dialog/select_templets.php file of the vulnerable DedeCMS version.
2. The attacker sends the crafted URL to an unsuspecting user or uses other social engineering techniques to entice the user to click on the link.
3. Upon execution, the payload allows an attacker to access sensitive directories on the targeted system by exploiting the path traversal vulnerability.

Mitigation

To protect your DedeCMS installation from being exploited via CVE-2023-2059, the following mitigations are recommended:

Update DedeCMS to the latest version, which includes patches for known vulnerabilities.

2. Implement proper input validation and sanitization for user inputs, particularly affecting the uploads/include/dialog/select_templets.php file.
3. Restrict access to sensitive directories by configuring proper access control policies on your web server.
4. Regularly monitor your server logs for any signs of unauthorized access attempts, intrusion, or suspicious activities.

Conclusion

The CVE-2023-2059 vulnerability in DedeCMS 5.7.87 poses a serious risk to the affected systems due to its potential impact on unauthorized data access and manipulation. Therefore, it is crucial to understand the consequences of this vulnerability, apply the necessary mitigations, and stay updated with the latest security patches to protect your systems from being compromised by attackers. Following best security practices and adopting a proactive approach to web security will go a long way in minimizing the risks associated with such vulnerabilities.

Timeline

Published on: 04/14/2023 15:15:00 UTC
Last modified on: 04/22/2023 02:35:00 UTC