Security readout for executives and security teams
Plain-English summary
FortiOS SSL VPN versions before 7.0.1 used a hard-coded cryptographic key. If recovered through reverse engineering, that key could expose sensitive SSL VPN confidentiality. The available sources identify this as a high-severity issue affecting Fortinet FortiOS before 7.0.1.
Executive priority
Treat this as a high-priority remediation item for any Fortinet SSL VPN still below FortiOS 7.0.1, especially internet-facing systems. The main business risk is confidentiality loss tied to cryptographic key exposure.
Technical view
CVE-2021-26108 is a FortiOS SSLVPN hard-coded cryptographic key issue. The CVSS 3.1 vector is network exploitable, low complexity, unauthenticated, no user interaction, with high confidentiality impact and no integrity or availability impact. Sources list affected versions as FortiOS before 7.0.1.
Likely exposure
Organizations running Fortinet FortiOS SSL VPN on versions before 7.0.1 are the relevant exposure group. Public-facing SSL VPN deployments should be prioritized because the CVSS vector is network-based and unauthenticated.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The CVSS metadata lists exploit code maturity as functional, but no offensive details are provided in the sources.
Researcher notes
Evidence is concise: hard-coded key, retrievable by reverse engineering, FortiOS before 7.0.1. No CWE is listed in the bundle. Do not claim active exploitation from the provided sources; KEV is false.
Mitigation direction
- Upgrade FortiOS SSL VPN systems to 7.0.1 or later.
- Review Fortinet FortiGuard advisory FG-IR-21-051 for vendor-specific guidance.
- Prioritize internet-facing SSL VPN appliances before internal-only systems.
- Restrict SSL VPN exposure where operationally feasible until upgraded.
Validation and detection
- Inventory FortiOS SSL VPN appliances and record exact firmware versions.
- Flag any FortiOS SSL VPN version earlier than 7.0.1.
- Confirm upgraded systems report FortiOS 7.0.1 or later.
- Check whether SSL VPN interfaces are exposed to the internet.
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-2021-26108 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/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:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:U/RC:C3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:U/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://fortiguard.com/advisory/FG-IR-21-051CVE 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.