CVE-2021-24237 in Realteo Plugin
Summary
by MITRE • 04/23/2021
The Realteo WordPress plugin before 1.2.4, used by the Findeo Theme, did not properly sanitise the keyword_search, search_radius. _bedrooms and _bathrooms GET parameters before outputting them in its properties page, leading to an unauthenticated reflected Cross-Site Scripting issue.
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Analysis
by VulDB Data Team • 04/27/2021
The CVE-2021-24237 vulnerability affects the Realteo WordPress plugin version 1.2.3 and earlier, which is utilized by the Findeo Theme for property listing websites. This security flaw represents a classic reflected cross-site scripting vulnerability that occurs when user input is not properly sanitized before being rendered in web pages. The vulnerability specifically impacts the plugin's properties page functionality where it processes GET parameters without adequate validation or sanitization measures.
The technical flaw manifests through the improper handling of several GET parameters including keyword_search, search_radius, _bedrooms, and _bathrooms. When these parameters are passed to the plugin's properties page, the plugin directly incorporates their values into HTML output without sufficient sanitization. This creates an opportunity for attackers to inject malicious JavaScript code through crafted URLs that exploit the reflected XSS vulnerability. The vulnerability is unauthenticated, meaning any visitor to the website can potentially exploit it without requiring valid credentials or privileges.
The operational impact of this vulnerability extends beyond simple script execution as it can enable attackers to perform various malicious activities including session hijacking, credential theft, defacement of the website content, or redirection to malicious sites. An attacker could craft a malicious URL containing JavaScript payloads that would execute in the victim's browser when the page loads, potentially stealing cookies or session tokens. The reflected nature of the vulnerability means that the malicious script is reflected back to the user through the web application's response, making it particularly dangerous for web applications that display user-provided data.
From a cybersecurity perspective, this vulnerability maps directly to CWE-79 which defines Cross-Site Scripting as a weakness in web applications where untrusted data is incorporated into web pages without proper validation or escaping. The ATT&CK framework categorizes this under T1566.001 - Phishing, as attackers could use this vulnerability to deliver malicious payloads through crafted URLs that appear legitimate to users. The vulnerability also aligns with T1059.007 - Command and Scripting Interpreter: JavaScript, as the attack vector involves executing JavaScript code within user browsers.
The recommended mitigation strategy involves updating the Realteo plugin to version 1.2.4 or later, which contains the necessary sanitization fixes for the affected GET parameters. Additionally, administrators should implement input validation at multiple layers including server-side parameter sanitization, output encoding for all dynamic content, and regular security audits of third-party plugins. Implementing Content Security Policy (CSP) headers can provide an additional layer of protection against XSS attacks by restricting the sources from which scripts can be loaded. Organizations should also consider implementing web application firewalls to detect and block malicious requests targeting known XSS attack patterns.