CVE-2018-5661 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 logo_width parameter.
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Analysis
by VulDB Data Team • 12/23/2019
The vulnerability identified as CVE-2018-5661 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 WordPress installations. This issue specifically manifests through the wp-admin/admin.php endpoint where the logo_width parameter fails to properly sanitize user input, creating an avenue for malicious actors to inject arbitrary JavaScript code into the administrative interface.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious payload and injects it through the logo_width parameter in the administrative URL. Since the plugin does not implement proper input validation or output escaping mechanisms for this parameter, the injected code executes within the context of the victim administrator's browser session. This allows attackers to perform actions such as stealing administrative credentials, modifying plugin settings, or redirecting users to malicious websites while operating under the privileges of the authenticated administrator.
From an operational standpoint, this vulnerability poses significant risk to WordPress sites that utilize the affected plugin, as it requires minimal effort for exploitation and can lead to complete administrative compromise. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage. The attack vector is particularly dangerous because it leverages the administrative interface where users typically have elevated privileges, making the impact of successful exploitation much more severe than typical user-facing XSS vulnerabilities.
The attack surface is further expanded by the fact that WordPress administrative interfaces are often accessible to users with lower privileges who may inadvertently trigger the vulnerability through social engineering or by visiting compromised sites. Security professionals should note that this vulnerability demonstrates the critical importance of input validation and output escaping in web applications, particularly within administrative interfaces where the potential for damage is amplified. The remediation approach requires immediate patching of the plugin to version 1.1.19 or later, which addresses the input sanitization issue by properly escaping the logo_width parameter before rendering it in the administrative interface.
Organizations should also implement additional defensive measures such as monitoring for unusual administrative activity, implementing web application firewalls to detect and block malicious payloads, and ensuring that all WordPress plugins are regularly updated to their latest secure versions. The vulnerability highlights the necessity of comprehensive security testing including parameter validation checks, and serves as a reminder that even seemingly minor input fields within administrative interfaces can represent significant security risks when proper sanitization controls are absent. This case study underscores the importance of following secure coding practices and adhering to OWASP Top Ten security guidelines for preventing XSS vulnerabilities in web applications.