CVE-2021-3163

Public Exploit

Description

A vulnerability in the HTML editor of Slab Quill 4.8.0 allows an attacker to execute arbitrary JavaScript by storing an XSS payload (a crafted onloadstart attribute of an IMG element) in a text field. Note: Researchers have claimed that this issue is not within the product itself, but is intended behavior in a web browser

Category

6.1
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.50%
Third-Party Advisory blogspot.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://quilljs.com product
https://burninatorsec.blogspot.com/2021/04/cve-2021-3163-xss-slab-quill-js.html third party advisory exploit
https://github.com/quilljs/quill/issues/3273 issue tracking third party advisory broken link
https://github.com/quilljs/quill/issues/3364 issue tracking exploit third party advisory

Frequently Asked Questions

What is the severity of CVE-2021-3163?
CVE-2021-3163 has been scored as a medium severity vulnerability.
How to fix CVE-2021-3163?
To fix CVE-2021-3163, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-3163 being actively exploited in the wild?
It is possible that CVE-2021-3163 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.