CVE-2019-3501 in OUGC Awards Plugin
Summary
by MITRE
The OUGC Awards plugin before 1.8.19 for MyBB allows XSS via a crafted award reason that is mishandled on the awards page or in a user profile.
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Analysis
by VulDB Data Team • 08/30/2025
The CVE-2019-3501 vulnerability affects the OUGC Awards plugin version 1.8.18 and earlier in the MyBB forum software ecosystem, representing a critical cross-site scripting flaw that undermines user security and data integrity. This vulnerability specifically targets the plugin's handling of award reasons within the awards page and user profile functionalities, creating a persistent vector for malicious actors to inject and execute arbitrary JavaScript code in the context of affected user sessions. The vulnerability exists due to insufficient input validation and output sanitization mechanisms within the plugin's codebase, allowing attackers to craft malicious award reasons that bypass security controls and execute within the browser of unsuspecting users.
The technical exploitation of this vulnerability occurs when the plugin fails to properly sanitize user-supplied award reason data before rendering it in HTML contexts. Attackers can craft award reasons containing malicious script payloads that get executed when other users view the awards page or user profiles containing these crafted entries. The flaw operates at the application layer where user input is processed without adequate security measures, making it particularly dangerous as it can be exploited through legitimate plugin functionality rather than requiring additional attack vectors. This type of vulnerability aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') and represents a classic example of how insufficient data sanitization can create persistent security weaknesses in web applications.
The operational impact of CVE-2019-3501 extends beyond simple script execution, as it can enable attackers to perform session hijacking, steal user credentials, redirect victims to malicious sites, or manipulate forum content to spread further attacks. The vulnerability affects all users who view award information within the MyBB platform, making it a widespread concern that can compromise multiple user sessions simultaneously. Attackers could leverage this vulnerability to create persistent backdoors within the forum environment, potentially leading to complete system compromise if the forum administrators are tricked into viewing malicious award entries. The attack surface is particularly concerning in community forums where users frequently interact and share information, as the vulnerability can be exploited through normal forum operations without requiring special privileges or complex attack chains.
Mitigation strategies for CVE-2019-3501 primarily involve immediate plugin updates to version 1.8.19 or later, which contain proper input sanitization and output encoding mechanisms. System administrators should implement additional security measures including content security policy headers, input validation at multiple layers, and regular security audits of third-party plugins. The vulnerability demonstrates the importance of maintaining up-to-date software components and implementing robust security controls for user-generated content processing. Organizations should also consider implementing web application firewalls and monitoring for suspicious activity related to award submissions. From an ATT&CK framework perspective, this vulnerability maps to T1566 - Phishing and T1059 - Command and Scripting Interpreter, as it enables initial access through social engineering and persistent execution through malicious script injection, highlighting the need for comprehensive security awareness training and application security controls.