How severe is CVE-2021-40834?

CVE-2021-40834 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2021-40834 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40834?

CVE-2021-40834 affects F-secure Safe. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40834?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-40834 published?

CVE-2021-40834 was published on 2021-12-10 and last updated on 2026-06-17.

CVE-2021-40834

CVE-2021-40834 is a medium-severity vulnerability in F-secure Safe with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1021.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1021
Affected product: F-secure Safe
Published: 2021-12-10
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-40834?: 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.
How severe is CVE-2021-40834?: CVE-2021-40834 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2021-40834 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40834?: CVE-2021-40834 affects F-secure Safe. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40834?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40834 published?: CVE-2021-40834 was published on 2021-12-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:f-secure:safe:*:*:*:*:*:android:*:*

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