CVE-2021-27821: openwrt luci Cross-site Scripting
CVSS: 6.1v3.1MediumModified
Published 25-05-2021Last modified 09-07-2026
Vulnerability summary
CVE-2021-27821 is a medium (CVSS 6.1) Cross-site Scripting vulnerability in openwrt luci. EPSS estimates a 0.59% chance of exploitation in the next 30 days, higher than 47.2% of scored vulnerabilities.
CVSS score
6.1/10
010
Medium · v3.1 (NVD)EPSS score
0.59%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 25-05-2021PublishedVulnerability first disclosed.
- 09-07-2026Last modifiedVulnerability information updated.
Description
The Web Interface for OpenWRT LuCI version 19.07 and lower has been discovered to have a cross-site scripting vulnerability.
CVSS metrics
2 scores · 1 source · 2 versionsMedium 6.1Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NSourcesSingle source
Medium 4.3Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:N/I:P/A:NSourcesSingle source
EPSS trend
Probability
0.59%
Chance of exploitation in the next 30 days
Percentile
47%
Versus all other CVEs
30-day change
0.00 pp
From 0.59% on 19-09-2026
19-09-202619-10-2026
EPSS score0.59%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Openwrt1 product
- luci≤ 19.07.0
1 vendor · 1 product