Security readout for executives and security teams
Plain-English summary
This flaw affects older Fortinet FortiClient EMS and FortiClient endpoint software. A nearby unauthenticated attacker could intercept telemetry traffic between EMS and clients, potentially altering or disrupting management communications. The risk is high where affected versions remain deployed on reachable internal networks.
Executive priority
Treat this as a high-priority internal exposure issue, especially for environments relying on FortiClient EMS for endpoint management. Prioritize inventory and vendor-guided upgrades before assuming compensating controls are sufficient.
Technical view
CVE-2021-41028 combines hard-coded cryptographic key use in FortiClientEMS with improper certificate validation in FortiClient for Windows, Linux, and Mac. A network-adjacent unauthenticated attacker may perform man-in-the-middle attacks against the EMS-to-FCT telemetry protocol. CVSS 3.1 score is 8.2, with high integrity and availability impact.
Likely exposure
Exposure is most likely in organizations running FortiClientEMS 7.0.1 or below, 6.4.6 or below, and FortiClient endpoints at matching affected versions. Risk depends on whether an attacker can become network-adjacent to EMS-client telemetry traffic.
Exploitation context
The CVE record describes possible unauthenticated network-adjacent man-in-the-middle exploitation. The source bundle does not identify known active exploitation, and KEV status is false. Attack complexity is rated high, so practical exploitation likely requires favorable network positioning.
Researcher notes
Evidence supports a chained design/validation weakness in telemetry trust: CWE-321 in EMS and CWE-297 in FortiClient. Public details in the bundle are limited, so validation should stay version-based and configuration-focused without assuming additional affected products or exploit maturity.
Mitigation direction
- Inventory FortiClientEMS and FortiClient endpoint versions across all platforms.
- Check Fortinet advisory FG-IR-21-075 for vendor-supported upgrade guidance.
- Upgrade affected EMS and endpoint versions beyond the listed vulnerable releases.
- Restrict access to EMS-client telemetry paths to trusted network segments.
- Monitor for unusual EMS-client telemetry failures or certificate validation anomalies.
Validation and detection
- Confirm whether FortiClientEMS is version 7.0.1 or below, or 6.4.6 or below.
- Confirm FortiClient Windows, Linux, and Mac versions against affected ranges.
- Map network paths where clients communicate with EMS telemetry services.
- Review whether untrusted users can access adjacent network segments.
- Verify remediation status against Fortinet's published advisory.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2021-41028 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H/E:F/RL:U/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H/E:F/RL:U/RC:C1.66Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H/E:F/RL:U/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.com/advisory/FG-IR-21-075CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.