CVE-2021-30533

Name: CVE-2021-30533
Creator: NVD / NIST
Published: 2021-06-07T20:15:08.73+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10Actively ExploitedEPSS 16.61%

Last modified Jun 17, 2026

CVE-2021-30533 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Insufficient policy enforcement in PopupBlocker in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass navigation restrictions via a crafted iframe.. CISA has confirmed active exploitation in the wild. EPSS estimates a 16.61% chance of exploitation in the next 30 days.

Description

Insufficient policy enforcement in PopupBlocker in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass navigation restrictions via a crafted iframe.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

16.61%

96.6th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jul 18, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Google	Chrome	< 91.0.4472.77
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34

References

https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.htmlRelease Notes, Vendor Advisory
https://crbug.com/1145553Exploit, Issue Tracking, Patch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/Mailing List, Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/Mailing List, Release Notes
https://security.gentoo.org/glsa/202107-06Third Party Advisory
https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.htmlRelease Notes, Vendor Advisory
https://crbug.com/1145553Exploit, Issue Tracking, Patch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/Mailing List, Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/Mailing List, Release Notes
https://security.gentoo.org/glsa/202107-06Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30533US Government Resource

Timeline

Published: Jun 7, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-30533?

Insufficient policy enforcement in PopupBlocker in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass navigation restrictions via a crafted iframe.

How severe is CVE-2021-30533?

CVE-2021-30533 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 16.61% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-30533?

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-2021-30533?

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

Scan your code now

Source: NVD / NIST