CVE-2017-12810 in PHP Newsletter Script
Summary
by MITRE
PHPJabbers PHP Newsletter Script 4.2 has stored XSS in lists in the admin panel.
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Analysis
by VulDB Data Team • 12/18/2019
The vulnerability CVE-2017-12810 represents a stored cross-site scripting flaw within the PHPJabbers PHP Newsletter Script version 4.2, specifically affecting the admin panel's list management functionality. This security weakness allows authenticated attackers with administrative privileges to inject malicious scripts into the application's database through the list creation or modification processes. The vulnerability resides in how the application handles user input when processing list data, failing to properly sanitize or escape special characters before storing them in the database. When other users or administrators view these maliciously crafted list entries, the stored scripts execute in their browsers, potentially leading to unauthorized actions or data theft.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding mechanisms within the admin panel's list handling code. The application does not sufficiently filter or escape HTML characters, JavaScript code, or other potentially dangerous input elements when processing list names, descriptions, or other editable fields. This failure to implement proper sanitization techniques creates an environment where malicious payloads can persist in the database and execute whenever the affected list data is rendered in the user interface. The vulnerability is classified as stored XSS due to the persistence of the malicious code, which remains in the database until actively removed by administrators.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with potential access to sensitive administrative functions and user data. An attacker who successfully exploits this vulnerability could manipulate list entries to redirect users to malicious websites, steal session cookies, or perform unauthorized actions within the newsletter system. The stored nature of the vulnerability means that the malicious code can affect multiple users over time, making it particularly dangerous for systems with numerous administrators or users who frequently interact with the list management features. This vulnerability can be exploited to escalate privileges or establish persistent access to the compromised system.
Mitigation strategies for CVE-2017-12810 should focus on implementing comprehensive input sanitization and output encoding practices throughout the application. Organizations should ensure that all user-supplied data is properly validated and escaped before being stored in the database, particularly in fields that will be rendered in HTML contexts. The implementation of Content Security Policy headers can provide additional protection against XSS attacks by restricting script execution. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other application components. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and it maps to ATT&CK technique T1059.007 for scripting languages, particularly focusing on web application exploitation. System administrators should also ensure that all third-party applications are regularly updated and patched, as this vulnerability was present in version 4.2 but likely addressed in subsequent releases through proper input validation implementations.