MEDIUM
CVE-2021-40834
CWE-1021Published: December 10, 2021· Updated: Jun 17, 2026
4.3
CVSS v3.1
Official 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.
Technical Analysis
CVE-2021-40834 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Affected Vendors & Products
f-secure1 product(s)
safe
Source: NVD CPE · 1 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories
All References (4)
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Quick Facts
CVE IDCVE-2021-40834
CVSS Score4.3 / 10
SeverityMEDIUM
WeaknessCWE-1021
CISA KEVNo
Affected1 vendor(s)
PublishedDec 10, 2021
Related CVEs (CWE-1021)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-40834 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.