CVE-2017-18488 in Backup Guard Plugin
Summary
by MITRE
The Backup Guard plugin before 1.1.47 for WordPress has multiple XSS issues.
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Analysis
by VulDB Data Team • 11/25/2023
The Backup Guard plugin for WordPress contains multiple cross-site scripting vulnerabilities that affect versions prior to 1.1.47, representing a significant security risk for WordPress installations. These vulnerabilities arise from insufficient input validation and output encoding within the plugin's administrative interfaces and frontend components, creating opportunities for attackers to inject malicious scripts that execute in the context of authenticated users' browsers. The flaw specifically manifests when the plugin processes user-supplied data without proper sanitization, allowing malicious actors to craft payloads that can be executed when legitimate users view affected pages or interact with plugin functionality.
The technical implementation of these XSS vulnerabilities stems from improper handling of untrusted data within the plugin's codebase, particularly in parameters used for configuration settings, backup scheduling, and administrative interfaces. Attackers can exploit these weaknesses by crafting malicious input through various plugin forms, API endpoints, or configuration parameters that are subsequently rendered back to users without adequate HTML escaping or context-appropriate encoding. This allows for the execution of arbitrary JavaScript code within the victim's browser session, potentially enabling session hijacking, credential theft, or redirection to malicious sites. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and represents a classic example of unsafe direct object reference or improper output encoding issues.
The operational impact of these vulnerabilities extends beyond simple script execution, as they can be leveraged to escalate privileges within the WordPress environment. An attacker who successfully exploits these XSS flaws can potentially access administrative functions, modify backup configurations, or gain unauthorized access to sensitive data stored within the WordPress installation. When combined with other attack vectors, these vulnerabilities can facilitate more sophisticated attacks such as privilege escalation or data exfiltration. The attack surface is particularly concerning given that Backup Guard is a backup plugin, meaning that successful exploitation could provide attackers with access to critical system backups, potentially compromising the entire recovery infrastructure. According to ATT&CK framework, these vulnerabilities map to T1059.007 for scripting and T1566 for spearphishing with a link, as they enable attackers to deliver malicious payloads through compromised plugin interfaces.
Mitigation strategies should prioritize immediate patching to version 1.1.47 or later, which addresses the identified XSS vulnerabilities through proper input validation and output encoding mechanisms. Administrators should also implement additional security controls including web application firewalls, input sanitization at the application level, and regular security auditing of WordPress plugins. Network-level protections such as content security policies can provide additional defense-in-depth measures, while monitoring for suspicious plugin activity and user behavior should be implemented. Regular security assessments of third-party plugins, including vulnerability scanning and code review processes, are essential for maintaining WordPress security posture. Organizations should also consider implementing automated patch management systems to ensure timely updates of all WordPress components and plugins, as these vulnerabilities could be exploited by automated scanning tools that target known vulnerable plugin versions.