CVE-2023-2225 in SEO Alert Plugin
Summary
by MITRE • 08/16/2023
The SEO ALert WordPress plugin through 1.59 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).
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Analysis
by VulDB Data Team • 04/27/2025
The SEO ALert WordPress plugin version 1.59 contains a critical stored cross-site scripting vulnerability that affects high-privilege users including administrators. This flaw exists within the plugin's handling of user settings where insufficient sanitization and escaping mechanisms are implemented, creating an attack vector that persists across user sessions. The vulnerability specifically targets the plugin's administrative interface where settings are stored and later rendered without proper output encoding, allowing malicious scripts to be injected and executed when affected pages are accessed.
The technical nature of this vulnerability stems from the plugin's failure to properly validate and sanitize user input before storing it in the WordPress database. When administrators modify plugin settings through the web interface, the data flows directly into the system without adequate sanitization processes that would normally prevent malicious code injection. This represents a classic stored xss flaw where the malicious payload is saved server-side and executed whenever the affected page content is rendered to users with appropriate privileges.
The operational impact of this vulnerability extends beyond simple script execution as it can be leveraged for privilege escalation within WordPress environments, particularly in multisite configurations where unfiltered_html capabilities are restricted. Attackers with administrator access can inject malicious scripts that persist across sessions and potentially compromise user data, modify content, or redirect users to malicious sites. The vulnerability is especially concerning in multisite setups where the restriction of unfiltered_html capability should normally prevent such attacks but fails due to the plugin's inadequate input handling.
This vulnerability aligns with CWE-79 which defines cross-site scripting flaws as the result of insufficient sanitization of user-provided data. It also maps to ATT&CK technique T1059.002 for command and script injection, specifically targeting web application interfaces where administrative functions are performed. The attack chain typically involves an authenticated administrator accessing the plugin settings, injecting malicious javascript code through the vulnerable input fields, and then having that code execute whenever other users access pages containing the stored content.
Mitigation strategies should include immediate patching of the plugin to version 1.60 or later where sanitization mechanisms have been properly implemented. Organizations should also implement additional defensive measures such as restricting administrative privileges to essential personnel only, implementing web application firewalls to detect and block suspicious script patterns, and conducting regular security audits of installed plugins. Regular monitoring of WordPress core and plugin updates, along with maintaining current security configurations that restrict unnecessary capabilities, forms the foundation of defense against this class of vulnerability. The incident highlights the critical importance of proper input validation and output escaping practices in web application development, particularly for administrative interfaces where privileged access exists.