CVE-2018-5660 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 coming-soon_sub_title parameter.
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Analysis
by VulDB Data Team • 12/23/2019
The vulnerability identified as CVE-2018-5660 resides within the responsive-coming-soon-page plugin version 1.1.18 for WordPress, representing a classic cross-site scripting flaw that undermines the security integrity of affected web applications. This issue manifests specifically through the wp-admin/admin.php endpoint where the coming-soon_sub_title parameter fails to properly sanitize user input, creating an exploitable vector for malicious actors to inject arbitrary script code into the administrative interface. The vulnerability operates at the application layer and directly impacts the plugin's handling of administrative inputs, making it particularly dangerous given that it targets the WordPress admin panel where privileged users typically interact with the system.
The technical implementation of this XSS vulnerability stems from inadequate input validation and output encoding practices within the plugin's codebase. When administrators navigate to the coming soon page settings through the wp-admin/admin.php interface and manipulate the coming-soon_sub_title parameter, the system fails to properly escape or filter special characters that could be interpreted as executable script code. This weakness allows attackers to craft malicious payloads that, when executed in the context of an authenticated administrator's browser session, can perform actions such as stealing session cookies, modifying plugin settings, or redirecting users to malicious domains. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications, and aligns with ATT&CK technique T1213 which covers data from information repositories.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with potential access to sensitive administrative functions within the WordPress environment. An attacker who successfully exploits this vulnerability could gain unauthorized access to the coming soon page configuration, potentially disabling the page or redirecting visitors to malicious content while maintaining persistent access through stolen administrative credentials. The attack requires minimal privileges since it targets the admin interface, and the exploitation process can be automated through web-based attack tools. The vulnerability affects all WordPress installations using the vulnerable plugin version, making it particularly widespread and concerning for organizations that have not yet updated their plugin repositories. Organizations may face reputational damage, data exfiltration, or complete system compromise if this vulnerability is exploited successfully.
Mitigation strategies for CVE-2018-5660 should prioritize immediate plugin updates to versions that address the XSS vulnerability, as the vendor has likely released patches to resolve the input sanitization issues. System administrators should implement comprehensive input validation measures that enforce strict character encoding and filtering for all administrative parameters, particularly those related to text input fields. Network-based defenses such as web application firewalls can provide additional protection by detecting and blocking malicious payloads targeting the specific parameter. Regular security audits and penetration testing should include verification of plugin security posture, with particular attention to administrative interfaces where privileged access exists. The vulnerability also underscores the importance of maintaining updated WordPress core installations and plugins, as outdated software components often contain known vulnerabilities that attackers actively exploit. Organizations should implement principle of least privilege for administrative accounts and consider multi-factor authentication to reduce the impact of potential credential compromise. Additionally, security monitoring should be enhanced to detect unusual administrative activities that may indicate exploitation attempts, and regular security training for administrators can help prevent social engineering attacks that might leverage this vulnerability.