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Fencer Intel
medium 4.3

CVE-2021-44751 json

F-Secure SAFE Browser vulnerable to USSD attacks

published 4y ago modified 4mo ago also EUVD-2021-31566

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

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.

Patch / fix

  • F-Secure F-Secure SAFE Browser for Android Version 18.5 & below 18.6

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Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • F-Secure F-Secure SAFE Browser for Android Version 18.5 & below

Classification

Weakness
  • CWE-276 Incorrect Default Permissions

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.