CVE-2018-13423 in Omeka
Summary
by MITRE
admin/themes/default/items/tag-form.php in Omeka before 2.6.1 allows XSS by adding or editing a tag.
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Analysis
by VulDB Data Team • 04/05/2023
The vulnerability identified as CVE-2018-13423 affects Omeka versions prior to 2.6.1 and represents a cross-site scripting flaw within the administrative theme component of the content management system. This issue specifically resides in the file admin/themes/default/items/tag-form.php which handles the rendering of tag forms for item management. The vulnerability arises from insufficient input validation and output sanitization mechanisms that fail to properly escape user-supplied data before it is rendered back to the browser. When administrators or users with appropriate privileges add or edit tags through the web interface, malicious payloads can be injected that will execute in the context of other users' browsers. This particular flaw falls under the CWE-79 category of Cross-Site Scripting, which is classified as a critical security weakness in web applications where untrusted data is directly incorporated into web pages without proper validation or encoding.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it can enable attackers to escalate privileges and gain unauthorized access to administrative functions. An attacker who successfully exploits this vulnerability can execute malicious scripts that may steal session cookies, redirect users to phishing sites, or perform actions on behalf of authenticated users within the Omeka system. The attack vector is particularly concerning because it targets the administrative interface where users have elevated privileges, potentially allowing full system compromise. According to ATT&CK framework, this vulnerability maps to T1059.008 for script injection techniques and T1566 for credential access through social engineering. The flaw is particularly dangerous in environments where multiple administrators interact with the system, as a single compromised user account could provide attackers with access to sensitive content management functions.
Mitigation strategies for CVE-2018-13423 require immediate implementation of the official patch released by Omeka version 2.6.1, which addresses the input validation issues in the tag-form.php file. Organizations should also implement additional defensive measures including input sanitization at multiple layers, output encoding for all dynamic content, and regular security audits of web applications. The vulnerability demonstrates the importance of proper context-aware encoding in web applications, where data must be properly escaped based on the target execution context such as HTML, JavaScript, or URL contexts. Security teams should also consider implementing web application firewalls and content security policies to provide additional protection against similar injection attacks. Regular vulnerability assessments and security training for administrators can help prevent exploitation of such flaws, as the vulnerability requires minimal skill to exploit and can be automated through various attack frameworks. The incident underscores the critical need for maintaining up-to-date software versions and implementing defense-in-depth strategies to protect content management systems from persistent threats.