CVE-2021-33594Network attack vector

Address bar spoofing via cross-domain overlay

Published Aug 11, 2021 · Updated Aug 3, 2024

Address bar spoofing in F-Secure Mobile Security 18.3x for Android allows remote attackers to show malicious content under a trusted URL. Safe Browser displays cross-domain content in a covering window while leaving a legitimate-looking address visible from the original page. Exploitation requires a user to click a crafted URL; the resulting origin deception can support phishing or unauthorized actions under the displayed site's identity.

CVSS severity3.5
Low
EPSS probability1.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Address bar spoofing in F-Secure Mobile Security 18.3x for Android allows remote attackers to show malicious content under a trusted URL. Safe Browser displays cross-domain content in a covering window while leaving a legitimate-looking address visible from the original page. Exploitation requires a user to click a crafted URL; the resulting origin deception can support phishing or unauthorized actions under the displayed site's identity.

The record

CVE
CVE-2021-33594
Published
Aug 11, 2021
Updated
Aug 3, 2024
Vendor
F-Secure
Product
F-Secure Mobile Security
Classifications
Unavailable
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=18.4x <18.3x*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

F-Secure · F-Secure Mobile Securityversion=18.4x <18.3x*

Published CVSS scores

3.5NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
3.5F-SecureCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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