---
title: "CVE-2021-30533: Incorrect Authorization | CubePath"
description: "Insufficient policy enforcement in PopupBlocker in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass navigation restrictions…"
language: en
source: https://cubepath.com/security/cve/CVE-2021-30533
---

# CVE-2021-30533: Incorrect Authorization | CubePath

## 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.

Official description from the CVE record, published by Chrome. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2021-30533)

## Key data

### CVSS 3.1 Medium 6.5

Score published by CISA-ADP in the CVE record.

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

| Metric                 | Value     | What it means                                                                       |
| ---------------------- | --------- | ----------------------------------------------------------------------------------- |
| Attack vector          | Network   | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity      | Low       | No special conditions are needed. The attack can be repeated at will.               |
| Privileges required    | None      | No account or privileges are needed.                                                |
| User interaction       | Required  | A user has to do something first, such as opening a file or following a link.       |
| Scope                  | Unchanged | The impact stays within the vulnerable component.                                   |
| Confidentiality impact | None      | No effect on the secrecy of data.                                                   |
| Integrity impact       | High      | Serious or total effect on the trustworthiness of data.                             |
| Availability impact    | None      | No effect on availability.                                                          |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.16742 (16.7% probability)

Percentile

97.1%

Scores of

Nov 10, 2026

Model

v2026.06.15

### CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog

Google Chromium PopupBlocker Security Bypass Vulnerability

Added to the catalog

Jun 27, 2022

Federal due date

Jul 18, 2022

### CISA assessment as of Feb 4, 2025

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation

Recorded by CISA as active

Automatable

no

Technical impact

partial

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-863](https://cwe.mitre.org/data/definitions/863.html) Incorrect Authorization

## Affected products

Products listed in the CVE record, as the CNA published them.

- Google Chrome

  - affected: unspecified up to before 91.0.4472.77

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [chromereleases.googleblog.com/2021/05/stable-channel-update…](https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop%5F25.html)
- [crbug.com/1145553](https://crbug.com/1145553)
- [GLSA-202107-06](https://security.gentoo.org/glsa/202107-06)  (security.gentoo.org) vendor-advisory
- [FEDORA-2021-f94dadff78](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/)  (lists.fedoraproject.org) vendor-advisory
- [FEDORA-2021-ca58c57bdf](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/)  (lists.fedoraproject.org) vendor-advisory

## Timeline

1. ID reserved Apr 13, 2021
2. Record published Jun 7, 2021
3. Added to CISA KEV Jun 27, 2022
4. Record last updated Oct 21, 2025

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:28 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)