Secuno
ENNL
Book demo

CVE-2021-30533

Google Chromium PopupBlocker Security Bypass

6.5 MEDIUMActively exploited (CISA KEV)Public exploitEPSS 16.7%
  1. Published7 Jun 2021
  2. Added to CISA KEV27 Jun 2022
  3. Remediation due18 Jul 2022
Actively exploited (CISA KEV)

Google Chromium PopupBlocker contains an insufficient policy enforcement vulnerability that allows a remote attacker to bypass navigation restrictions via a crafted iframe. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.

Added to KEV: 27 Jun 2022Federal remediation due: 18 Jul 2022

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeUnchanged
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected products

Google Chrome< 91.0.4472.77
Fedoraproject Fedora33 · 34

Remediation

Fixed in
Google Chrome≥ 91.0.4472.77

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-163018.5
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.7 before…
CVE-2026-1095598.7
EdgeEver Desktop 1.6.26 through 1.112.0 contains a navigation allowlist bypass that…
CVE-2026-773669.9
obsidian-tc is a governed, agent-ready Model Context Protocol server for Obsidian…
CVE-2026-1039038.8
An incorrect authorization vulnerability in the WinBox authentication flow of MikroTik…
CVE-2026-1087468.8
Vearch 3.5.2 through 3.5.9 contains an incorrect authorization vulnerability in…
CVE-2026-816499.1
The Fundiin cho WooCommerce WordPress plugin through 3.4.0 does not have proper…

Frequently asked

Is CVE-2021-30533 being actively exploited?

Yes. CVE-2021-30533 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 27 Jun 2022.

How severe is CVE-2021-30533?

CVE-2021-30533 has a CVSS 3.1 base score of 6.5, rated medium. EPSS estimates a 16.7% probability of exploitation.

Which products are affected by CVE-2021-30533?

Affected products include Google Chrome, Fedoraproject Fedora.

How do I fix CVE-2021-30533?

Upgrade affected software to a fixed version, for example Google Chrome 91.0.4472.77 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-30533 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.