CVE-2011-4342 in BackWPup
Summary
by MITRE
PHP remote file inclusion vulnerability in wp_xml_export.php in the BackWPup plugin before 1.7.2 for WordPress allows remote attackers to execute arbitrary PHP code via a URL in the wpabs parameter.
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Analysis
by VulDB Data Team • 01/30/2025
The vulnerability identified as CVE-2011-4342 represents a critical remote file inclusion flaw within the BackWPup WordPress plugin ecosystem. This vulnerability specifically affects versions prior to 1.7.2 and resides in the wp_xml_export.php file, which serves as a component for exporting WordPress data. The flaw stems from inadequate input validation and sanitization mechanisms that fail to properly filter user-supplied data before using it in file inclusion operations. Attackers can exploit this weakness by crafting malicious URLs and injecting them through the wpabs parameter, effectively bypassing normal security controls that would typically prevent arbitrary code execution.
The technical nature of this vulnerability aligns with CWE-88, which describes improper neutralization of special elements used in an expression, specifically in the context of command and control operations. This vulnerability falls under the broader category of remote code execution through insecure file inclusion, a pattern that has been consistently documented in web application security assessments and represents one of the most dangerous classes of vulnerabilities. The exploitation mechanism relies on the plugin's failure to validate the wpabs parameter against a whitelist of acceptable URLs or paths, allowing attackers to inject external URLs that are then processed through PHP's include or require functions.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise. When successfully exploited, attackers can execute arbitrary PHP code on the affected WordPress installation, potentially leading to unauthorized access, data theft, website defacement, or the establishment of persistent backdoors. The vulnerability affects not just individual WordPress sites but represents a significant risk to any system administrator who fails to update their plugins to the patched version. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring local access or credentials, making it particularly dangerous for web applications that are publicly accessible.
Mitigation strategies for CVE-2011-4342 should prioritize immediate patching of the BackWPup plugin to version 1.7.2 or later, which contains the necessary input validation fixes. Additionally, implementing proper parameter validation and sanitization measures within the WordPress plugin architecture can help prevent similar vulnerabilities from emerging in other components. Security monitoring should include detection of suspicious URL patterns in plugin parameters and implementation of web application firewalls that can block known malicious payloads. Organizations should also consider implementing the principle of least privilege for WordPress plugin installations and regularly audit their plugin ecosystem for outdated or vulnerable components. This vulnerability demonstrates the critical importance of keeping WordPress plugins updated and maintaining comprehensive security practices that include regular vulnerability assessments and automated patch management systems. The ATT&CK framework categorizes this vulnerability under T1190 for Exploit Public-Facing Application, highlighting the need for organizations to maintain robust perimeter defenses and conduct regular security testing of their web applications to prevent exploitation of such remote code execution vulnerabilities.