CVE-2022-1827 in PDF24 Article To PDF Plugin
Summary
by MITRE • 06/20/2022
The PDF24 Article To PDF WordPress plugin through 4.2.2 does not have CSRF check in place when updating its settings, which could allow attackers to make a logged in admin change them via a CSRF attack
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Analysis
by VulDB Data Team • 06/20/2022
The PDF24 Article To PDF WordPress plugin version 4.2.2 and earlier contains a critical security flaw that stems from the absence of Cross-Site Request Forgery (CSRF) protection mechanisms within its administrative settings update functionality. This vulnerability resides in the plugin's handling of administrative operations, specifically when users attempt to modify plugin configurations while authenticated within the WordPress administration interface. The lack of CSRF protection creates a significant attack surface that adversaries can exploit to manipulate plugin settings without the knowledge or consent of legitimate administrators. According to the Common Weakness Enumeration catalog, this flaw corresponds to weakness type CWE-352, which categorizes Cross-Site Request Forgery vulnerabilities as a fundamental web application security issue. The vulnerability operates by tricking authenticated administrators into executing unintended actions through maliciously crafted requests that appear to originate from legitimate administrative sessions. Attackers can leverage this weakness by constructing specially crafted web pages or email attachments that, when visited by an authenticated admin user, automatically submit malicious requests to the WordPress plugin settings endpoint.
The operational impact of this vulnerability extends beyond simple configuration changes, as it can potentially enable more sophisticated attack vectors within the WordPress environment. When an administrator visits a compromised page or clicks on malicious links, the CSRF attack can silently modify plugin settings, potentially redirecting content processing, altering output formats, or changing security configurations that could affect the entire WordPress installation. The vulnerability is particularly dangerous because it requires no authentication credentials from the attacker, relying instead on the administrator's existing authenticated session to execute malicious operations. This aligns with the ATT&CK framework's technique T1078.004, which describes the use of valid accounts for lateral movement and privilege escalation within compromised environments. The attack scenario typically involves the administrator being tricked into visiting a malicious website that contains hidden iframe elements or JavaScript code designed to submit requests to the vulnerable plugin's settings update endpoint. These requests can modify critical plugin parameters that may affect content processing, document generation, or even enable other attack vectors through compromised plugin functionality.
Mitigation strategies for this vulnerability must address both the immediate exposure and broader security posture of the WordPress installation. The most effective immediate solution involves updating the PDF24 Article To PDF plugin to version 4.2.3 or later, where the CSRF protection mechanisms have been implemented. Organizations should also implement comprehensive monitoring of administrative activities and settings changes to detect unauthorized modifications that may indicate a successful CSRF attack. Network-based security controls such as web application firewalls can provide additional protection by filtering suspicious requests that attempt to modify administrative settings without proper CSRF tokens. Security teams should also consider implementing Content Security Policy (CSP) headers that restrict the sources from which scripts can be loaded, reducing the effectiveness of malicious CSRF attacks that rely on embedded scripts. The vulnerability highlights the importance of proper input validation and security token implementation in WordPress plugins, particularly those handling administrative functions. Organizations should conduct regular security assessments of their WordPress plugin ecosystem, ensuring that all third-party plugins maintain up-to-date security practices and implement proper CSRF protection mechanisms. Additionally, administrators should be trained to recognize potentially malicious websites and avoid visiting untrusted sources that could host CSRF attack vectors. The incident underscores the necessity of maintaining current security practices and the critical role that proper authentication token implementation plays in preventing unauthorized administrative operations.