Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-21187

18
FAUCET Score

CVE-2021-21187 is a medium-severity vulnerability in Google Chrome versions prior to 89.0.4389.72, affecting various Debian and Fedora distributions. It stems from insufficient data validation in URL formatting, allowing remote attackers to perform domain spoofing through IDN homographs via crafted domain names. The attack requires user interaction (UI:R) and has a low impact on integrity (I:L), with no impact on confidentiality or availability. There is no evidence of active exploitation, nor are there publicly available exploit codes like Metasploit or Nuclei modules, despite some community discussion and media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
< 89.0.4389.72CPE matchmatch criteria
cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
32CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
34CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
10.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

4.3MEDIUM

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
Exploitability Score
2.8
Impact Score
1.4
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.45%
Probability of exploitation in next 30 days
EPSS Percentile
70.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0145 is in the 83rd percentile among its peer group of 26,236 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Vendor Patches (1)

googlevendor investigatingvia nvd_reference
View patch

Vendor Advisories (1)

microsoft2021-Mar/CVE-2021-21187

Chromium CVE-2021-21187: Insufficient data validation in URL formatting

Mar 9, 2021

References

chromereleases.googleblog.com / 2021/03/stable-channel-update-for-desktop.html
Release NotesVendor Advisory
crbug.com / 1155516
Permissions Required
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/BBT54RKAE5XLMWSHLVUKJ7T2XHHYMXLH
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/FE5SIKEVYTMDCC5OSXGOM2KRPYLHYMQX
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/LCIDZ77XUDMB2EBPPWCQXPEIJERDNSNT
security.gentoo.org / glsa/202104-08
Third Party Advisory
debian.org / security/2021/dsa-4886
Third Party Advisory