CVE-2018-5212 in Simple Download Monitor Plugin
Summary
by MITRE
The Simple Download Monitor plugin before 3.5.4 for WordPress has XSS via the sdm_upload_thumbnail (aka File Thumbnail) parameter in an edit action to wp-admin/post.php.
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Analysis
by VulDB Data Team • 01/20/2023
The CVE-2018-5212 vulnerability represents a cross-site scripting flaw in the Simple Download Monitor WordPress plugin affecting versions prior to 3.5.4. This vulnerability specifically targets the plugin's administrative interface where users can edit posts containing download files. The flaw exists in how the plugin handles the sdm_upload_thumbnail parameter within the wp-admin/post.php endpoint during edit operations. When an attacker crafts a malicious request containing XSS payload within this parameter, the vulnerability allows arbitrary JavaScript execution in the context of an authenticated administrator's browser session.
The technical implementation of this vulnerability stems from insufficient input validation and output sanitization within the plugin's file thumbnail upload handling mechanism. The sdm_upload_thumbnail parameter, which is used to store thumbnail image URLs for download files, fails to properly escape or validate user-supplied data before rendering it back to the browser. This creates an environment where malicious actors can inject HTML and JavaScript code that executes when administrators view the affected edit pages. The vulnerability is particularly concerning because it requires only a single parameter manipulation to achieve its effect, making it relatively easy to exploit in targeted attacks.
From an operational perspective, this vulnerability poses significant risks to WordPress installations using the Simple Download Monitor plugin. An attacker who gains access to an administrator's session through social engineering or other means can leverage this XSS flaw to perform actions such as modifying plugin settings, stealing administrative credentials, or redirecting users to malicious websites. The impact extends beyond simple data theft as the attacker can potentially establish persistent backdoors or escalate privileges within the WordPress environment. The vulnerability also aligns with attack patterns documented in the ATT&CK framework under the T1059 technique for command and control through browser-based attacks, and T1546 for persistence mechanisms.
The vulnerability has clear mappings to CWE categories including CWE-79 Cross-site Scripting - Reflected and CWE-352 Cross-Site Request Forgery, as it enables attackers to execute malicious scripts in the context of authenticated users. Organizations using this plugin should immediately implement the patch released in version 3.5.4 which addresses the input sanitization issues by properly escaping output and validating all user-supplied parameters. Additionally, administrators should consider implementing web application firewalls, monitoring for suspicious parameter values, and conducting regular security audits of WordPress plugins. The vulnerability demonstrates the critical importance of input validation in web applications and highlights why regular patch management and security updates are essential for maintaining secure WordPress environments.