Executive Summary
A critical stored cross-site scripting (XSS) vulnerability exists in HeyForm, an open-source form builder, prior to version 3.0.0-rc.7. This vulnerability allows a low-privileged team member to inject malicious JavaScript that executes when a team owner views the form, potentially leading to complete account takeover through privilege escalation.
Technical Analysis
The vulnerability is classified as a stored cross-site scripting (XSS) issue. The attack vector involves a low-privileged team member injecting malicious JavaScript into the form builder. This malicious code is then executed when a team owner views the form. The root cause of this vulnerability is the lack of proper input validation and sanitization in the form builder feature of HeyForm.
How It Gets Exploited
An attacker with low privileges as a team member can inject malicious JavaScript into the form builder. When a team owner views the form, the malicious code is executed, potentially allowing the attacker to escalate privileges and take over the account. The exploitation requires the attacker to have access to the form builder and for the team owner to view the form.
Impact Assessment
The vulnerability affects HeyForm versions prior to 3.0.0-rc.7. The CVSS score for this vulnerability is 9, indicating a critical severity level. An attacker can achieve high impact on confidentiality, integrity, and availability. The blast radius is significant as it can lead to complete account takeover through privilege escalation.
Recommended Actions
To mitigate this vulnerability, update HeyForm to version 3.0.0-rc.7 or later. Additionally, ensure that only trusted team members have access to the form builder feature, and monitor for any suspicious activity in the form builder.
Sources
- National Vulnerability Database (NVD)
- GitHub Security Advisory: GHSA-chmm-jqpm-3pwx