CVE-2021-27821

Name: CVE-2021-27821
Creator: NVD / NIST
Published: 2021-05-25T14:15:07.51+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.79%

Last modified Jun 17, 2026

CVE-2021-27821 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. The Web Interface for OpenWRT LuCI version 19.07 and lower has been discovered to have a cross-site scripting vulnerability which can lead to attackers carrying out arbitrary code execution.. EPSS estimates a 0.79% chance of exploitation in the next 30 days.

Description

The Web Interface for OpenWRT LuCI version 19.07 and lower has been discovered to have a cross-site scripting vulnerability which can lead to attackers carrying out arbitrary code execution.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.79%

51.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Openwrt	Luci	<= 19.07.0

References

http://openwrt.comVendor Advisory
http://openwrtorg.comBroken Link
http://openwrt.comVendor Advisory
http://openwrtorg.comBroken Link

Timeline

Published: May 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-27821?

The Web Interface for OpenWRT LuCI version 19.07 and lower has been discovered to have a cross-site scripting vulnerability which can lead to attackers carrying out arbitrary code execution.

How severe is CVE-2021-27821?

CVE-2021-27821 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.79% probability of exploitation in the next 30 days.

How do I fix CVE-2021-27821?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-27821?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST