CVE-2015-9430 in crazy-bone Plugin
Summary
by MITRE
The crazy-bone plugin before 0.6.0 for WordPress has XSS via the User-Agent HTTP header.
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Analysis
by VulDB Data Team • 12/28/2023
The crazy-bone plugin for WordPress represents a significant security vulnerability that existed prior to version 0.6.0, specifically targeting the User-Agent HTTP header as an attack vector for cross-site scripting exploits. This vulnerability demonstrates how seemingly innocuous HTTP headers can become pathways for malicious code execution when proper input validation and sanitization measures are absent from web applications. The plugin's failure to adequately filter or escape user-supplied data within the User-Agent header creates a persistent XSS threat that can be exploited across multiple user sessions and browsing contexts.
The technical flaw stems from the plugin's improper handling of HTTP headers during request processing, where the User-Agent string is directly incorporated into the web application's output without sufficient sanitization. This primitive input validation approach allows attackers to inject malicious JavaScript code through the User-Agent header when making HTTP requests to WordPress sites running the vulnerable plugin. The vulnerability operates under CWE-79 which specifically addresses cross-site scripting flaws, where the application fails to properly sanitize user-controllable data before incorporating it into dynamically generated web pages. The attack mechanism leverages the fact that many web applications store and display User-Agent information in administrative interfaces or log files, making it susceptible to XSS exploitation.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, redirect users to malicious websites, steal sensitive cookies, or execute arbitrary commands within the victim's browser context. When an administrator or authenticated user visits a page that displays the User-Agent information, the injected JavaScript executes in their browser, potentially leading to complete compromise of their session. This vulnerability particularly affects WordPress installations where the plugin is active and where administrative users might be logged in, creating a high-impact threat that can escalate to full system compromise. The persistent nature of XSS vulnerabilities means that any user who encounters the malicious User-Agent header during browsing operations becomes a potential victim, making this attack vector particularly dangerous in environments with multiple concurrent users.
Mitigation strategies for this vulnerability involve immediate patching to version 0.6.0 or later, which should include proper input sanitization and output encoding for all HTTP headers. Security practitioners should implement comprehensive header validation mechanisms that filter out potentially malicious content before processing user-supplied data. Additionally, organizations should consider implementing Content Security Policy headers to limit script execution capabilities, and establish monitoring procedures to detect unusual User-Agent patterns that might indicate exploitation attempts. The vulnerability highlights the importance of following secure coding practices as outlined in OWASP Top 10 and ATT&CK framework techniques related to web application exploitation, particularly the T1212 technique for exploitation of web applications through input validation flaws. Regular security assessments and vulnerability scanning should include checks for outdated plugins and proper header sanitization practices to prevent similar issues from occurring in other components of the web application stack.