CVE-2018-20837 in Typesetter
Summary
by MITRE
include/admin/Menu/Ajax.php in Typesetter 5.1 has index.php/Admin/Menu/Ajax?cmd=AddHidden title XSS.
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Analysis
by VulDB Data Team • 09/15/2023
The vulnerability identified as CVE-2018-20837 affects Typesetter version 5.1 and resides within the administrative interface component located at include/admin/Menu/Ajax.php. This flaw manifests when processing requests through the URL path index.php/Admin/Menu/Ajax?cmd=AddHidden, where the application fails to properly sanitize user input before incorporating it into HTML output. The vulnerability specifically targets the title parameter, which when manipulated can lead to cross-site scripting attacks. This represents a critical security oversight in the content management system's administrative functionality.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the Ajax handler responsible for managing menu items. When an attacker submits a malicious title value through the AddHidden command, the system stores this input without adequate sanitization measures. The stored value is then later rendered in the administrative interface without proper HTML escaping or encoding, creating an environment where malicious JavaScript code can execute within the context of other users' browser sessions. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws, and more precisely maps to CWE-79-HTMLTags as it involves improper handling of HTML content in user-supplied data.
The operational impact of this vulnerability extends beyond simple data theft or defacement. An authenticated attacker with administrative privileges could leverage this flaw to execute arbitrary JavaScript code in the browser of other administrators or users with access to the same administrative interface. This could result in session hijacking, privilege escalation, or the ability to modify critical system configurations. The attack vector requires minimal user interaction since the vulnerability exists within the administrative interface where legitimate users would naturally navigate. The vulnerability also aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: JavaScript, as it enables the execution of malicious javascript payloads through the web interface.
Mitigation strategies for this vulnerability should begin with immediate patching of the Typesetter 5.1 installation to the latest available version that addresses this specific flaw. Organizations should implement input validation at multiple layers, including server-side sanitization of all user-supplied data before storage and proper HTML encoding before output rendering. The implementation of Content Security Policy headers can provide additional defense-in-depth measures to prevent unauthorized script execution. Regular security audits of web applications should include thorough testing of all Ajax endpoints and administrative interfaces to identify similar input handling vulnerabilities. Additionally, implementing proper access controls and monitoring for unusual administrative activities can help detect exploitation attempts. The vulnerability demonstrates the importance of following secure coding practices and the principle of least privilege in web application development, particularly within administrative interfaces where the potential impact of exploitation is significantly elevated.