CVE-2021-21283 : Security Advisory and Response
Learn about CVE-2021-21283 involving a cross-site scripting vulnerability in the Flarum Sticky extension. Understand its impact, technical details, and how to mitigate the risk.
Flarum is an open source discussion platform for websites. The "Flarum Sticky" extension versions 0.1.0-beta.14 and 0.1.0-beta.15 has a cross-site scripting vulnerability. Learn about the impact, technical details, and mitigation of this CVE below.
Understanding CVE-2021-21283
This section will cover what CVE-2021-21283 is, its impact, technical details, and how to mitigate the risk.
What is CVE-2021-21283?
CVE-2021-21283 involves a cross-site scripting vulnerability in the Flarum Sticky extension affecting versions 0.1.0-beta.14 and 0.1.0-beta.15, enabling attackers to perform XSS attacks.
The Impact of CVE-2021-21283
The vulnerability allows malicious JavaScript execution through HTML attribute injection in pinned discussions, potentially compromising user data and site integrity.
Technical Details of CVE-2021-21283
Explore the vulnerability description, affected systems, versions, and exploitation mechanism to understand the technical specifics of CVE-2021-21283.
Vulnerability Description
The vulnerability results from injected plain text content rendering as HTML, facilitating XSS attacks, ultimately enabling malicious script execution.
Affected Systems and Versions
Flarum Sticky extension versions 0.1.0-beta.14 and 0.1.0-beta.15 are affected, leaving websites vulnerable to XSS attacks.
Exploitation Mechanism
By leveraging the injected HTML content, attackers can run JavaScript code through certain HTML attributes, leading to potential XSS exploits.
Mitigation and Prevention
Implement immediate steps and long-term security practices to mitigate the risk and prevent future vulnerabilities.
Immediate Steps to Take
Administrators should disable the Flarum Sticky extension until applying the official fix in version v0.1.0-beta.16 or the back-ported patch in v0.1.0-beta.15.1.
Long-Term Security Practices
Regularly update extensions, monitor pinned discussions for suspicious edits, and follow secure coding practices to prevent XSS vulnerabilities.
Patching and Updates
Forum administrators must promptly apply the forthcoming update in Flarum beta 16 or utilize the provided back-ported patch for beta 15 to address the XSS vulnerability.