CVE-2023-28994 in UX-themes Flatsome Plugin
Summary
by MITRE • 08/23/2023
Unauth. Reflected Cross-Site Scripting (XSS) vulnerability in UX-themes Flatsome plugin <= 3.16.8 versions.
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Analysis
by VulDB Data Team • 09/16/2023
The CVE-2023-28994 vulnerability represents a critical unauthenticated reflected cross-site scripting flaw discovered in the UX-themes Flatsome WordPress plugin version 3.16.8 and earlier. This vulnerability resides within the plugin's handling of user input parameters that are reflected back to users without proper sanitization or output encoding. The Flatsome plugin is widely used across WordPress installations for its theme customization capabilities and e-commerce features, making this vulnerability particularly concerning as it affects a substantial number of websites. The vulnerability specifically manifests when malicious actors craft specially crafted URLs containing script payloads that are then reflected back to unsuspecting users who visit the malicious links. This type of vulnerability allows attackers to execute arbitrary JavaScript code in the context of a victim's browser, potentially leading to session hijacking, credential theft, or further exploitation of the compromised user's privileges.
The technical implementation of this vulnerability stems from improper input validation and output encoding practices within the plugin's core functionality. When users access certain plugin endpoints with maliciously crafted parameters, the system fails to adequately sanitize the input before reflecting it back in the HTTP response. This creates an environment where attacker-controlled script code can be executed within the browser context of legitimate users. The vulnerability operates under CWE-79 which specifically addresses Cross-Site Scripting flaws in software applications. The reflected nature of this vulnerability means that the malicious payload must be delivered to the target through social engineering tactics such as phishing emails, compromised websites, or malicious advertisements. Attackers typically leverage this vulnerability by crafting URLs that contain JavaScript payloads designed to exploit the reflected XSS flaw. The vulnerability is classified as unauthenticated because no prior access or credentials are required to exploit it, making it particularly dangerous as it can be exploited by anyone who can influence user behavior through malicious links or content.
The operational impact of CVE-2023-28994 extends beyond simple script execution, as it provides attackers with a foothold for more sophisticated attacks within compromised user sessions. When successful, the vulnerability can enable attackers to steal session cookies, redirect users to malicious sites, modify page content, or perform actions on behalf of authenticated users. The potential for credential theft increases significantly as attackers can capture login credentials or manipulate the authentication flow. Additionally, the vulnerability can serve as a launching point for further attacks such as privilege escalation or data exfiltration. The widespread adoption of the Flatsome plugin means that numerous WordPress sites could be affected, potentially creating a large attack surface for threat actors. The vulnerability's impact is further amplified when considering that many WordPress installations lack proper security monitoring or input validation mechanisms, making detection and prevention more challenging. Organizations running vulnerable versions of the plugin face significant risk of compromise, particularly those with high-value user data or those that rely heavily on user authentication and session management.
Mitigation strategies for CVE-2023-28994 require immediate action from affected organizations to update to patched versions of the Flatsome plugin. The most effective immediate solution involves upgrading to version 3.16.9 or later, which contains the necessary security patches to prevent the reflected XSS vulnerability. Organizations should also implement comprehensive input validation and output encoding measures across their web applications, ensuring that all user-supplied data is properly sanitized before being processed or displayed. Security headers such as Content Security Policy (CSP) can provide additional protection by limiting the sources from which scripts can be executed, thereby reducing the impact of successful XSS attacks. Regular security assessments and vulnerability scanning should be implemented to identify similar flaws in other components of the web application stack. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for "Scripting" within the Execution phase, indicating that attackers can leverage this vulnerability to execute malicious scripts against users. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts and provide additional layers of defense. Regular patch management processes should be established to ensure timely application of security updates and prevent similar vulnerabilities from remaining unpatched for extended periods.