CVE-2018-5666 in responsive-coming-soon-page Plugin
Summary
by MITRE
An issue was discovered in the responsive-coming-soon-page plugin 1.1.18 for WordPress. XSS exists via the wp-admin/admin.php bg_color parameter.
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Analysis
by VulDB Data Team • 12/23/2019
The vulnerability identified as CVE-2018-5666 resides within the responsive-coming-soon-page plugin version 1.1.18 for WordPress, representing a cross-site scripting flaw that allows attackers to inject malicious scripts into web pages viewed by other users. This particular vulnerability manifests through the wp-admin/admin.php endpoint where the bg_color parameter fails to properly sanitize user input, creating an avenue for persistent script injection attacks that can compromise user sessions and potentially escalate to full system compromise.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within the plugin's administrative interface. When administrators or users navigate to the wp-admin/admin.php page and provide a malicious value for the bg_color parameter, the application processes this input without sufficient sanitization measures. This failure to properly encode or validate the parameter value allows malicious scripts to be executed in the context of the victim's browser, enabling attackers to perform actions such as stealing cookies, session tokens, or redirecting users to malicious sites. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and represents a classic case of insufficient output escaping in dynamic web content generation.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with a potential foothold for more sophisticated attacks within the WordPress environment. An attacker who successfully exploits this vulnerability could potentially steal administrator credentials, modify plugin configurations, or inject malicious content that affects all users of the affected website. The attack vector is particularly concerning because it targets the administrative interface, meaning that successful exploitation could lead to complete compromise of the WordPress installation. This vulnerability also aligns with ATT&CK technique T1213 which covers data from information repositories, as the compromised administrative access could lead to unauthorized data access and modification. The persistence of this vulnerability in the wp-admin area means that it could affect any user with administrative privileges who visits the affected page.
Mitigation strategies for CVE-2018-5666 should focus on immediate plugin updates to versions that properly sanitize the bg_color parameter and implement proper input validation. Organizations should also consider implementing web application firewalls that can detect and block malicious payloads targeting this specific parameter. Additionally, administrators should conduct thorough security audits of their WordPress installations to identify any other plugins or themes that might exhibit similar input validation flaws. The recommended approach includes disabling the vulnerable plugin until a patched version is installed, implementing proper input sanitization practices, and ensuring that all administrative interfaces properly encode output to prevent script injection. Regular security monitoring and vulnerability scanning should be implemented to detect similar issues in other components of the web application stack, as this vulnerability demonstrates the importance of comprehensive input validation across all user-controllable parameters in web applications.