dbcve.org
FortiwanApplication · Fortinet

CVE-2021-26115

HIGH · 7.8 CVSS v3.1 Published 2024-12-19
Fix available
A fix is available. Upgrade to 4.5.8 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An OS command injection (CWE-78) vulnerability in FortiWAN version 4.5.7 and below Command Line Interface may allow a local, authenticated and unprivileged attacker to escalate their privileges to root via executing a specially-crafted command.An OS command injection (CWE-78) vulnerability in FortiWAN Command Line Interface may allow a local, authenticated and unprivileged attacker to escalate their privileges to root via executing a specially-crafted command.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OS command injection vulnerability in FortiWAN CLI allows a local, authenticated unprivileged attacker to execute arbitrary OS commands and escalate to root privileges by injecting specially-crafted commands through the CLI interface.

MitigationApply vendor patch or upgrade FortiWAN to a version above 4.5.7; restrict CLI access to trusted personnel only until patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FortiwanApplication
Affected:< 4.5.8

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify FortiWAN installation and version
    Access the FortiWAN administrative interface or CLI and retrieve the firmware/software version information using the command 'get system status' or 'fwc -v' depending on available CLI access
    Affected if The displayed version number is lower than 4.5.8 (e.g., 4.5.7, 4.5.6, earlier versions)
  2. Confirm CLI interface is enabled
    Check the FortiWAN configuration for CLI access permissions using 'show system admin' or equivalent configuration review to see which users have CLI privilege level
    Affected if CLI access is granted to any user account, especially unprivileged or non-root accounts
  3. Verify user account privileges
    Review the list of configured administrator/user accounts and their assigned privilege levels through the web UI under User & Authentication or via CLI command 'get system admin'
    Affected if There exists any authenticated user account with CLI access that is not the super_admin or root account
  4. Check for recent CLI session logs
    Examine FortiWAN logs or audit trails for CLI command executions, looking for unusual or unexpected commands in the session logs accessible via the web UI log viewer or CLI 'execute log' commands
    Affected if Unusual command patterns or commands executed by non-privileged users appear in the logs

A FortiWAN deployment is affected if the installed version is below 4.5.8 and the CLI interface is accessible to authenticated users with limited privileges.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.5.8 or later
Fixed in 4.5.8
Interim mitigation

Apply vendor patch or upgrade FortiWAN to a version above 4.5.7; restrict CLI access to trusted personnel only until patch is applied.

Recommended fix High confidence

FortiWAN 4.5.8 or later

  1. Identify the current FortiWAN version by accessing the CLI or web interface
  2. Download FortiWAN version 4.5.8 or later from the Fortinet support portal (support.fortinet.com)
  3. Review Fortinet's upgrade documentation for FortiWAN before proceeding
  4. Execute the upgrade using FortiWAN's standard upgrade procedure via CLI or web interface
  5. After upgrade, verify the new version is 4.5.8 or later
  6. Confirm the CLI upgrade was successful and the system is operational

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Fortiwan Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-26115 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data