CVE-2022-2440 in Theme Editor Plugin
Summary
by MITRE • 08/29/2024
The Theme Editor plugin for WordPress is vulnerable to deserialization of untrusted input via the 'images_array' parameter in versions up to, and including 2.8. This makes it possible for authenticated attackers with administrative privileges to call files using a PHAR wrapper that will deserialize and call arbitrary PHP Objects that can be used to perform a variety of malicious actions granted a POP chain is also present. It also requires that the attacker is successful in uploading a file with the serialized payload.
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Analysis
by VulDB Data Team • 08/29/2024
The vulnerability identified as CVE-2022-2440 affects the Theme Editor plugin for WordPress, specifically targeting versions up to and including 28. This represents a critical security flaw that exploits the plugin's handling of untrusted input through the 'images_array' parameter during deserialization processes. The vulnerability requires an authenticated attacker with administrative privileges to exploit, making it particularly dangerous in environments where administrative access can be compromised or where attackers have already gained footholds within the system. The flaw falls under the category of insecure deserialization as defined by CWE-502, which occurs when applications deserialize untrusted data without proper validation or sanitization.
The technical exploitation of this vulnerability involves the attacker leveraging the PHAR wrapper functionality to execute malicious PHP objects through the deserialization process. When the plugin processes the 'images_array' parameter, it fails to properly validate or sanitize the input, allowing an attacker to inject serialized PHP objects that will be executed upon deserialization. This creates a path for arbitrary code execution and can potentially lead to complete system compromise. The requirement for a POP (Property Object Poisoning) chain indicates that the attacker must also successfully upload a file containing the serialized payload, which adds another layer of complexity to the attack but does not eliminate the severity of the vulnerability.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with the capability to perform a wide range of malicious actions within the WordPress environment. These actions can include but are not limited to data exfiltration, privilege escalation, backdoor installation, and persistence mechanisms. The vulnerability particularly affects WordPress sites that rely on the Theme Editor plugin for their functionality, potentially compromising thousands of websites if the plugin is widely used. The attack vector is particularly concerning because it requires only administrative privileges rather than elevated system access, making it accessible to attackers who have already gained access to administrative accounts through other means such as credential theft or social engineering attacks.
Mitigation strategies for CVE-2022-2440 should focus on immediate plugin updates to versions that address the deserialization vulnerability, as well as implementing comprehensive input validation and sanitization measures. Organizations should also enforce strict access controls and monitor for unauthorized administrative activities, as the vulnerability requires authenticated access to exploit. Additionally, implementing web application firewalls and security monitoring solutions can help detect and prevent exploitation attempts. The vulnerability aligns with ATT&CK technique T1548.002 which covers abuse of cloud service principals and T1059.007 which involves the use of PowerShell for execution, though the specific exploitation method here is more directly related to PHP deserialization attacks. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other plugins and themes that may be susceptible to the same class of deserialization flaws.