CVE-2021-41028

Telemetry interception via hard-coded key and certificate mismatch

Published Dec 16, 2021 · Updated Oct 25, 2024

Cryptographic flaws in FortiClientEMS and FortiClient 7.0.1 and earlier allow remote attackers to intercept telemetry traffic. EMS uses a hard-coded cryptographic key, while Windows, Linux, and macOS clients fail to validate that the EMS certificate matches its host. The attacker must occupy an adjacent network position between EMS and a managed client, enabling telemetry observation or modification.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cryptographic flaws in FortiClientEMS and FortiClient 7.0.1 and earlier allow remote attackers to intercept telemetry traffic. EMS uses a hard-coded cryptographic key, while Windows, Linux, and macOS clients fail to validate that the EMS certificate matches its host. The attacker must occupy an adjacent network position between EMS and a managed client, enabling telemetry observation or modification.

The record

CVE
CVE-2021-41028
Published
Dec 16, 2021
Updated
Oct 25, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-297, CWE-321, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 25, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.0FortinetCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H/E:F/RL:U/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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
CWE-321Use of Hard-coded Cryptographic Key
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo