dbcve.org
SafeApplication · F Secure

CVE-2021-44751

MEDIUM · 5.3 CVSS v3.1 Published 2022-03-25
Fix available
A fix is available. Upgrade to 18.5 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability affecting F-Secure SAFE browser was discovered. A maliciously crafted website attached with USSD code in JavaScript or iFrame can trigger dialer application from F-Secure browser which can be exploited by an attacker to send unwanted USSD messages or perform unwanted calls. In most modern Android OS, dialer application will require user interaction, however, some older Android OS may not need user interaction.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

F-Secure SAFE browser fails to properly validate or restrict malicious web content from invoking the device dialer via URI schemes (tel: or ussd:). A crafted website containing JavaScript or iFrame elements can automatically trigger the dialer to send USSD codes or initiate calls. On older Android versions, this occurs silently without user interaction, while modern versions may show a prompt.

MitigationUpdate F-Secure SAFE browser to the latest patched version. Until then, warn users against visiting untrusted websites and consider disabling JavaScript in the browser as a temporary workaround.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SafeApplication
Affected:< 18.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify F-Secure SAFE is installed
    Check your Android device settings under Apps or use a package manager command (e.g., `adb shell pm list packages | grep fsecure`) to confirm F-Secure SAFE is present on the device
    Affected if F-Secure SAFE is installed on the device
  2. Determine installed F-Secure SAFE version
    Open Google Play Store, search for F-Secure SAFE, and check the version number under app details, or use `adb shell dumpsys package com.fsecure.safe` to retrieve the installed version
    Affected if The installed version number is lower than 18.5
  3. Confirm browser component is active
    Check if the F-Secure SAFE in-app browser has been used or is accessible within the application (look for browser or safe browsing features in the app interface)
    Affected if The browser feature has been enabled or used within the app
  4. Check JavaScript execution state in the browser
    Within the F-Secure SAFE app, navigate to settings or browser settings to verify if JavaScript execution is allowed (note: the vulnerability can exploit both JavaScript and iFrame elements)
    Affected if JavaScript is enabled in the F-Secure SAFE browser settings

Your environment is affected if F-Secure SAFE with a version lower than 18.5 is installed and the in-app browser feature has been used or is accessible, regardless of JavaScript settings since iFrame elements can also trigger the vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 18.5 or later
Fixed in 18.5
Interim mitigation

Update F-Secure SAFE browser to the latest patched version. Until then, warn users against visiting untrusted websites and consider disabling JavaScript in the browser as a temporary workaround.

Recommended fix Moderate confidence

18.5

  1. Open the Google Play Store or app store on the Android device
  2. Search for F-Secure SAFE
  3. Tap on Update to install version 18.5 or later
  4. Alternatively, open F-Secure SAFE app and navigate to Settings > About > Check for updates
  5. Ensure the update completes successfully
  6. Restart the device if prompted to ensure all security patches are fully applied

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Safe Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-44751 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data