CVE-2021-22131

Information disclosure via certificate hostname mismatch

Published Jul 18, 2022 · Updated Oct 22, 2024

Improper certificate validation in FortiToken Mobile 5.0.3 and earlier allows remote attackers to disclose information via man-in-the-middle attacks. The client accepts certificates whose host name does not match the validation server, enabling an attacker on the adjacent network to impersonate that server and intercept protected exchanges. Exploitation requires a man-in-the-middle position and user interaction; the documented impact is information disclosure without integrity impact.

CVSS severity6.4
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in FortiToken Mobile 5.0.3 and earlier allows remote attackers to disclose information via man-in-the-middle attacks. The client accepts certificates whose host name does not match the validation server, enabling an attacker on the adjacent network to impersonate that server and intercept protected exchanges. Exploitation requires a man-in-the-middle position and user interaction; the documented impact is information disclosure without integrity impact.

The record

CVE
CVE-2021-22131
Published
Jul 18, 2022
Updated
Oct 22, 2024
Vendor
Fortinet
Product
FortiToken Mobile
Classifications
CWE-297, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=FortiTokenAndroid 5.0.3, 5.0.2, 4.5.0, 4.4.0, 4.3.0, 4.2.2, 4.2.1, 4.1.1, 4.0.1, 4.0.0, 3.0.4, 3.0.3, 3.0.2, 3.0.1, 3.0.0, 0.4.20, 0.4.10, FortiTokeniOS 5.2.0, 4.3.0, 4.2.0, 4.1.1, 3.0.5, 3.0.4, 3.0.3, 3.0.2, 3.0.1, FortiTokenWinApp 4.0.3, 3.0.1, 3.0.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Fortinet · FortiToken Mobileversion=FortiTokenAndroid 5.0.3, 5.0.2, 4.5.0, 4.4.0, 4.3.0, 4.2.2, 4.2.1, 4.1.1, 4.0.1, 4.0.0, 3.0.4, 3.0.3, 3.0.2, 3.0.1, 3.0.0, 0.4.20, 0.4.10, FortiTokeniOS 5.2.0, 4.3.0, 4.2.0, 4.1.1, 3.0.5, 3.0.4, 3.0.3, 3.0.2, 3.0.1, FortiTokenWinApp 4.0.3, 3.0.1, 3.0.0

Published CVSS scores

6.4Fortinet CNACVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:H
6.1Fortinet CNACVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:H/E:P/RL:X/RC:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-297Improper Validation of Certificate with Host Mismatch
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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