CVE-2021-34641 in SEOPress Plugin
Summary
by MITRE • 08/16/2021
The SEOPress WordPress plugin is vulnerable to Stored Cross-Site-Scripting via the processPut function found in the ~/src/Actions/Api/TitleDescriptionMeta.php file which allows authenticated attackers to inject arbitrary web scripts, in versions 5.0.0 - 5.0.3.
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Analysis
by VulDB Data Team • 08/19/2021
The vulnerability identified as CVE-2021-34641 affects the SEOPress WordPress plugin, specifically targeting versions 5.0.0 through 5.0.3. This issue represents a critical security flaw that enables authenticated attackers to execute malicious scripts within the context of affected WordPress installations. The vulnerability resides within the processPut function located in the ~/src/Actions/Api/TitleDescriptionMeta.php file, making it particularly dangerous as it operates at the core API processing layer of the plugin's functionality.
The technical implementation of this stored cross-site scripting vulnerability stems from inadequate input validation and output sanitization within the plugin's API handling mechanisms. When authenticated users with sufficient privileges interact with the plugin's title and description meta processing features, the system fails to properly sanitize user-supplied data before storing it in the database. This allows attackers to inject malicious JavaScript code that persists in the application's data store and executes whenever the affected content is retrieved and rendered in the user interface. The vulnerability's classification as stored XSS (CWE-79) means that the malicious payload is stored server-side and can affect multiple users who view the compromised content, rather than being limited to a single session or request.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to perform various malicious activities within the targeted WordPress environment. An attacker could leverage this vulnerability to steal administrative credentials, modify content, redirect users to malicious sites, or even establish persistent backdoors within the WordPress installation. The authenticated nature of the attack requires the attacker to already possess valid user credentials, but this limitation does not significantly reduce the threat level given that WordPress administrators often have elevated privileges and access to sensitive data. The vulnerability creates a pathway for privilege escalation and data exfiltration, making it particularly attractive to threat actors targeting WordPress-based websites.
Mitigation strategies for CVE-2021-34641 should prioritize immediate patching of the SEOPress plugin to version 5.0.4 or later, which contains the necessary fixes for the stored XSS vulnerability. Organizations should also implement additional defensive measures including regular security audits of WordPress plugins, monitoring for unauthorized modifications to plugin files, and enforcing strict access controls to prevent unauthorized user accounts from gaining administrative privileges. Network monitoring solutions should be configured to detect suspicious API requests that may indicate exploitation attempts, while web application firewalls can provide additional layers of protection by filtering malicious payloads before they reach the application server. The vulnerability's presence in the API processing layer also underscores the importance of implementing proper input validation at all levels of application processing, aligning with ATT&CK technique T1566.001 for credential access and T1059.001 for command and scripting interpreter usage patterns that attackers might employ to exploit such vulnerabilities.