CVE-2021-40834: User interface Spoofing in F-Secure SAFE browser for Android

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-12-10 · updated 2026-06-17
Weakness: CWE-1021

Description

A user interface overlay vulnerability was discovered in F-secure SAFE Browser for Android. When user click on a specially crafted seemingly legitimate URL SAFE browser goes into full screen and hides the user interface. A remote attacker can leverage this to perform spoofing attack.

Affected products

F-Secure SAFE Browser for Android Version 18.5: through 17.9

References

https://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fame
https://www.f-secure.com/en/business/support-and-downloads/security-advisories/cve-2021-40834
https://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fame
https://www.f-secure.com/en/business/support-and-downloads/security-advisories/cve-2021-40834

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