Concrete CMS Cross-Site Scripting Vulnerability Scanner

Concrete CMS is a robust content management system (CMS) that enables website developers and owners to easily build and manage dynamic websites. It is widely adopted for its user-friendly interface and flexibility, allowing the creation of a variety of web content, from simple blogs to comprehensive e-commerce platforms. Developers, content creators, and site administrators utilize Concrete CMS to craft intuitive websites that cater to the needs of diverse audiences. It supports a wide range of themes and plugins, enhancing its functionality and design capabilities. Being open-source, it has a vibrant community that contributes to its ongoing development and security.

The cross-site scripting (XSS) vulnerability in versions of Concrete CMS prior to 8.5.2 can allow attackers to execute arbitrary web scripts or HTML through a user's browser. This specific XSS flaw is located in the preview_as_user function, exploiting the cID parameter. Attackers can use this vulnerability to steal cookies, hijack sessions, redirect users to malicious websites, or display fraudulent content, all under the guise of the trusted website. The impact of exploiting this vulnerability can vary from stealing sensitive information to compromising user accounts.

This XSS vulnerability is triggered through the manipulation of the cID parameter in the preview_as_user function. By injecting a malicious script into the cID parameter, an attacker can cause the web application to execute the script within the context of the user's browser session. The vulnerability is due to the application’s failure to properly sanitize user-supplied input, allowing the attacker to insert HTML or script code that the browser will execute. This can lead to unauthorized actions being performed, personal data exposure, and manipulation of user sessions. Successful exploitation does not require authentication, making it a critical security concern.

Exploiting this vulnerability could lead to several adverse effects on both the website and its users. For users, this might include the theft of session tokens or cookies, leading to account compromise. For the website, it could result in the defacement of web pages, spreading of malware, or redirection of visitors to malicious sites. The credibility and trustworthiness of the website could be significantly damaged, potentially leading to a loss of users or revenue.

By subscribing to the securityforeveryone platform, users gain access to a sophisticated cyber threat exposure management service. This service not only identifies vulnerabilities like the XSS flaw in Concrete CMS but also provides detailed reports and actionable insights. Membership offers the benefit of continuous monitoring of digital assets against a wide array of security vulnerabilities, ensuring that users can proactively address issues before they are exploited. With securityforeveryone, organizations enhance their cybersecurity posture, safeguard digital assets, and maintain trust with their customers.

References

• https://hackerone.com/reports/643442
• https://github.com/concrete5/concrete5/pull/7999
• https://twitter.com/JacksonHHax/status/1389222207805661187