CVE-2023-5237 in Memberlite Shortcodes Plugin
Summary
by MITRE • 10/31/2023
The Memberlite Shortcodes WordPress plugin before 1.3.9 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admin.
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Analysis
by VulDB Data Team • 04/23/2025
The vulnerability identified as CVE-2023-5237 affects the Memberlite Shortcodes WordPress plugin version 1.3.8 and earlier, presenting a critical security risk through stored cross-site scripting flaws. This issue arises from insufficient input validation and output escaping mechanisms within the plugin's shortcode processing functionality. The vulnerability specifically targets the plugin's handling of shortcode attributes, where user-provided data is not adequately sanitized before being rendered back to users within the web page context. Attackers with contributor-level privileges can exploit this weakness to inject malicious scripts that persist in the database and execute whenever affected pages are loaded, creating a persistent threat vector that can compromise higher-privilege users.
The technical flaw stems from the plugin's failure to implement proper sanitization routines for shortcode parameters, which directly relates to CWE-79 - Improper Neutralization of Input During Web Page Generation. This weakness allows malicious code to be stored in the WordPress database through legitimate plugin functionality, making the attack a classic case of stored XSS. When administrators or other high-privilege users view pages containing the malicious shortcode, their browsers execute the injected scripts in the context of their sessions, potentially leading to complete account compromise, data exfiltration, or privilege escalation. The vulnerability's impact is amplified because it requires minimal privileges to exploit, making it particularly dangerous in environments where contributor accounts may have access to content creation features.
The operational implications of CVE-2023-5237 extend beyond simple script execution, as it enables attackers to perform sophisticated attacks against high-privilege users within the WordPress ecosystem. This includes session hijacking, privilege escalation, and data manipulation attacks that can compromise entire WordPress installations. The vulnerability creates a persistent threat vector because the malicious scripts are stored in the database rather than being transmitted through a single request, making detection more difficult and the attack surface broader. Security professionals should note that this vulnerability aligns with ATT&CK technique T1548.003 - Steal or Forge Authentication Tokens, as it can be used to hijack administrator sessions and gain unauthorized access to sensitive administrative functions.
Organizations affected by this vulnerability should immediately upgrade to Memberlite Shortcodes plugin version 1.3.9 or later, which implements proper input validation and output escaping mechanisms. The recommended mitigation strategy involves implementing comprehensive content security policies, monitoring for suspicious shortcode usage, and conducting regular security audits of installed plugins. Additional protective measures include restricting contributor privileges to minimize potential attack vectors, implementing web application firewalls to detect and block malicious script injection attempts, and establishing regular security scanning procedures for WordPress installations. The vulnerability demonstrates the critical importance of input validation and output escaping in web applications, particularly in content management systems where user-generated content processing occurs. Security teams should prioritize patching this vulnerability as a high-priority remediation item, given its ability to enable privilege escalation attacks with minimal attacker privileges and its potential to compromise entire WordPress installations through targeted attacks against administrative users.