CVE-2022-0879 in Caldera Forms Plugin
Summary
by MITRE • 04/18/2022
The Caldera Forms WordPress plugin before 1.9.7 does not validate and escape the cf-api parameter before outputting it back in the response, leading to a Reflected Cross-Site Scripting
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Analysis
by VulDB Data Team • 04/21/2022
The Caldera Forms WordPress plugin vulnerability CVE-2022-0879 represents a critical reflected cross-site scripting flaw that affects versions prior to 1.9.7. This vulnerability resides in the plugin's handling of the cf-api parameter within its API endpoints, where insufficient input validation and output escaping mechanisms leave the system susceptible to malicious code injection attacks. The issue manifests when the plugin processes API requests without properly sanitizing user-supplied input before incorporating it into HTTP responses, creating an attack vector that can be exploited by remote attackers to execute arbitrary JavaScript code in the context of a victim's browser.
The technical exploitation of this vulnerability occurs through the manipulation of the cf-api parameter in API requests sent to the Caldera Forms plugin endpoints. When an attacker crafts a malicious URL containing crafted script code within the cf-api parameter and delivers it to a victim, the vulnerable plugin fails to sanitize this input before echoing it back in the HTTP response. This reflected behavior allows attackers to inject malicious scripts that execute in the victim's browser when they click on the malicious link or visit the compromised page. The vulnerability directly maps to CWE-79: Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly escape or validate user input before incorporating it into web responses.
The operational impact of CVE-2022-0879 extends beyond simple script execution as it can enable attackers to perform various malicious activities including session hijacking, credential theft, defacement of web content, and redirection to malicious sites. Attackers can leverage this vulnerability to steal administrator credentials, modify form configurations, or inject malicious content that persists across user sessions. The reflected nature of the vulnerability means that the attack payload is not stored on the server but is instead reflected back in the HTTP response, making it particularly dangerous for targeted attacks and phishing campaigns. This vulnerability also aligns with ATT&CK technique T1566.001: Phishing, as it can be used to craft convincing malicious URLs that appear legitimate to users.
Mitigation strategies for this vulnerability primarily focus on immediate remediation through plugin updates to version 1.9.7 or later, which contains the necessary input validation and output escaping fixes. System administrators should also implement additional security measures including input validation at the web application firewall level, regular security audits of WordPress plugins, and monitoring for suspicious API requests containing unusual parameter values. The vulnerability demonstrates the importance of proper input sanitization and output escaping practices, which are fundamental to preventing cross-site scripting attacks. Organizations should also consider implementing Content Security Policy headers to add an additional layer of protection against script injection attacks, though this should not replace proper input validation. Regular security assessments of all WordPress plugins and themes remain essential to identify and remediate similar vulnerabilities before they can be exploited in the wild.