CVE-2018-5663 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 button_text_link parameter.
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Analysis
by VulDB Data Team • 12/23/2019
The vulnerability identified as CVE-2018-5663 resides within the responsive-coming-soon-page plugin version 1.1.18 for WordPress, representing a cross-site scripting weakness that compromises the security integrity of affected web applications. This issue manifests through the wp-admin/admin.php endpoint where the button_text_link parameter fails to properly sanitize user input, creating an exploitable vector for malicious actors to inject harmful scripts into the application's administrative interface. The vulnerability specifically affects WordPress installations that utilize this particular plugin version, making it a targeted risk for sites employing this specific software component.
The technical flaw stems from insufficient input validation and output escaping mechanisms within the plugin's administrative handling code. When administrators interact with the plugin's settings through the WordPress admin panel, the button_text_link parameter receives user-provided data without adequate sanitization processes. This failure allows attackers to inject malicious JavaScript code that executes within the context of the administrator's browser session. The vulnerability operates under CWE-79 which categorizes cross-site scripting flaws as weaknesses in input validation and output escaping, specifically targeting the improper handling of untrusted data in web applications. The attack vector requires minimal privileges since the vulnerability exists in the administrative interface, making it particularly dangerous as it can be exploited by users with limited access who may gain elevated privileges through successful exploitation.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform actions with the privileges of authenticated administrators. Successful exploitation could result in unauthorized modifications to website content, data exfiltration, credential theft, or even complete system compromise through session hijacking. The vulnerability's presence in a widely-used plugin means that numerous WordPress sites could be at risk simultaneously, creating a substantial attack surface for threat actors. Additionally, the administrative nature of the vulnerability means that the attack requires minimal user interaction beyond the initial injection, as the malicious script executes automatically when administrators view the affected plugin settings page. This characteristic aligns with ATT&CK technique T1059.007 which covers scripting languages and T1566.002 for credential access through social engineering, as the vulnerability can be leveraged to harvest administrator credentials or manipulate website content.
Mitigation strategies for CVE-2018-5663 should prioritize immediate plugin updates to versions that address the XSS vulnerability, as the developers have likely released patches to resolve the sanitization issues. Administrators should implement comprehensive input validation measures and ensure that all user-provided data is properly escaped before being rendered in administrative interfaces. Network-level protections such as web application firewalls can provide additional defense-in-depth measures by monitoring for suspicious parameter values in the admin.php endpoint. Regular security audits of installed plugins and themes should be conducted to identify and remediate similar vulnerabilities, with particular attention to input handling within administrative interfaces. The implementation of content security policies can further limit the impact of successful XSS attempts by restricting script execution within the browser context. Organizations should also establish secure coding practices that emphasize proper input validation and output escaping, particularly for parameters that are processed within administrative sections of web applications.