Security readout for executives and security teams
Plain-English summary
CVE-2021-26107 lets a restricted FortiManager user change VPN tunnel status outside their intended VDOM scope. This is not an unauthenticated internet takeover, but it can undermine segmentation and operational control if low-privileged administrator accounts exist.
Executive priority
Treat as a medium-priority administrative control issue. Prioritize environments where FortiManager manages multiple VDOMs or where many delegated administrators have VPN Manager access. The business concern is unauthorized disruption or manipulation of VPN tunnel status across segmentation boundaries.
Technical view
FortiManager 6.4.4 and 6.4.5 have improper access control in VPN Manager. An authenticated attacker with a restricted user profile may modify VPN tunnel status for other VDOMs. CVSS 3.1 is 6.3, with network access, low privileges, no user interaction, and low confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to organizations running FortiManager 6.4.4 or 6.4.5 with users who can authenticate to VPN Manager under restricted profiles. Multi-VDOM environments are most relevant because the issue crosses intended VDOM boundaries.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. Exploitation requires an authenticated FortiManager user with restricted access, so the main risk is insider misuse or compromise of a low-privileged administrative account.
Researcher notes
The source bundle names CWE-284 in the description but has an empty CWE list. Remediation details are not included in the bundle beyond the Fortinet advisory reference and CVSS remediation metric. Do not assume affected products beyond FortiManager 6.4.4 and 6.4.5.
Mitigation direction
- Inventory FortiManager deployments and identify versions 6.4.4 and 6.4.5.
- Review Fortinet advisory FG-IR-21-043 for the supported workaround or upgrade guidance.
- Restrict FortiManager login access to trusted administrative networks.
- Limit VPN Manager privileges for restricted profiles until remediation is applied.
- Review accounts with access across multi-VDOM management workflows.
Validation and detection
- Confirm FortiManager version and build on every management instance.
- Identify whether VPN Manager and multi-VDOM administration are enabled.
- Review restricted user profiles for VPN Manager permissions.
- Audit recent VPN tunnel status changes across VDOMs.
- Verify Fortinet-recommended remediation is applied and documented.
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-2021-26107 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:H/RL:W/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:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:H/RL:W/RC:C2.83.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:H/RL:W/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.com/advisory/FG-IR-21-043CVE 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.