CVE-2019-20211 in CTHthemes CityBook Theme
Summary
by MITRE
The CTHthemes CityBook before 2.3.4, TownHub before 1.0.6, and EasyBook before 1.2.2 themes for WordPress allow Persistent XSS via Listing Address, Listing Latitude, Listing Longitude, Email Address, Description, Name, Job or Position, Description, Service Name, Address, Latitude, Longitude, Phone Number, or Website.
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Analysis
by VulDB Data Team • 03/20/2024
This vulnerability affects multiple WordPress themes including CTHthemes CityBook prior to version 2.3.4, TownHub prior to version 1.0.6, and EasyBook prior to version 1.2.2, all of which are susceptible to persistent cross-site scripting attacks. The flaw stems from inadequate input validation and output sanitization mechanisms within the theme's listing management features. Attackers can inject malicious javascript code through various user input fields including listing addresses, geographic coordinates, email addresses, descriptions, names, job positions, service details, and contact information. These fields are particularly vulnerable because they accept user-supplied data without proper sanitization before being rendered on web pages, creating a persistent XSS vector that can affect all visitors to the compromised website.
The technical implementation of this vulnerability aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation, specifically manifesting as a persistent XSS flaw where malicious scripts are stored on the server and executed whenever users access affected pages. This vulnerability operates at the application layer and can be exploited through the standard web application attack surface. The vulnerability is particularly concerning because it affects administrative input fields that are commonly used by legitimate users to add business listings, service information, or contact details. When users visit pages containing maliciously injected scripts, the code executes in the context of their browser session, potentially leading to session hijacking, credential theft, or redirection to malicious sites.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to perform sophisticated attacks such as cookie theft, session manipulation, and data exfiltration. The persistent nature of the vulnerability means that once injected, malicious code remains active until manually removed from the database, making it particularly dangerous for website administrators who may not immediately detect the compromise. Attackers can leverage this vulnerability to create backdoors, harvest user credentials, or redirect visitors to phishing sites. The attack surface is broad given that multiple themes are affected and numerous input fields can be exploited, providing attackers with multiple vectors for compromise. This vulnerability directly maps to several ATT&CK techniques including T1566.001 - Phishing: Spearphishing Attachment and T1071.001 - Application Layer Protocol: Web Protocols, as it enables the delivery of malicious payloads through web-based interfaces.
Mitigation strategies should focus on immediate theme updates to versions 2.3.4, 1.0.6, and 1.2.2 respectively for the affected themes, as these releases contain the necessary input sanitization patches. Additionally, administrators should implement comprehensive input validation at the application level, ensuring all user-supplied data is properly escaped before database storage and output rendering. Regular security audits of theme and plugin code should be conducted to identify similar vulnerabilities, while implementing Content Security Policy headers can provide additional protection against XSS attacks. Database sanitization practices should be strengthened through proper parameterized queries and input filtering mechanisms. Organizations should also consider implementing web application firewalls and monitoring systems to detect and prevent exploitation attempts, while user access controls should be reviewed to limit administrative privileges to trusted individuals only.