CVE-2018-16626 in Typesetter
Summary
by MITRE
index.php/Admin/Classes in Typesetter 5.1 allows XSS via the description of a new class name.
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Analysis
by VulDB Data Team • 09/15/2023
The vulnerability CVE-2018-16626 represents a cross-site scripting flaw discovered in Typesetter version 5.1 within the administrative interface at the index.php/Admin/Classes endpoint. This issue specifically affects the handling of class descriptions when creating new class names, allowing authenticated attackers with administrative privileges to inject malicious script code that executes in the context of other users' browsers. The vulnerability exists due to insufficient input validation and output sanitization of user-supplied data within the administrative class creation functionality, creating a persistent XSS vector that can be exploited by malicious actors with access to the admin panel.
The technical implementation of this vulnerability stems from the application's failure to properly sanitize or escape user input when processing class descriptions in the administrative interface. When administrators create or modify class entries through the web interface, the system stores the provided description without adequate filtering of potentially dangerous characters or script tags. This allows attackers who have gained administrative access to inject malicious JavaScript code that gets stored and subsequently executed whenever other users view the affected class information. The vulnerability is classified as a persistent XSS attack since the malicious payload is stored server-side and executed against multiple users over time rather than requiring a single interaction.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to perform a wide range of malicious activities through the compromised administrative account. Attackers could steal session cookies, redirect users to malicious sites, modify class data, or even escalate privileges further within the application. The vulnerability affects all users who view the affected class descriptions, making it particularly dangerous in multi-user environments where administrators frequently create and maintain class information. According to CWE-79, this represents a classic cross-site scripting vulnerability that allows attackers to inject malicious code into web applications, while the ATT&CK framework would categorize this under T1059.007 for scripting languages and T1566 for spearphishing with a malicious attachment or link.
Mitigation strategies for CVE-2018-16626 should focus on implementing comprehensive input validation and output sanitization measures throughout the Typesetter application. Organizations should immediately apply the vendor-provided patch or upgrade to a secure version that properly escapes all user input before storage and rendering. The implementation should include proper HTML entity encoding of all user-supplied content, the use of Content Security Policy headers to limit script execution, and regular input validation to prevent malicious payloads from being accepted. Additionally, administrators should implement principle of least privilege controls to limit access to administrative functions, as the vulnerability requires authenticated access to exploit. Security monitoring should be enhanced to detect unusual administrative activities, and regular security audits should be conducted to identify similar input validation weaknesses in other parts of the application. The vulnerability demonstrates the critical importance of proper input sanitization in web applications, particularly within administrative interfaces where privileged access can lead to severe security consequences.