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FortisandboxApplication · Fortinet

CVE-2021-26105

HIGH · 8.8 CVSS v3.1 Published 2025-03-24
Fix available
A fix is available. Upgrade to 3.2.3 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
A stack-based buffer overflow vulnerability (CWE-121) in the profile parser of FortiSandbox version 3.2.2 and below, version 3.1.4 and below may allow an authenticated attacker to potentially execute unauthorized code or commands via specifically crafted HTTP requests.

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

A stack-based buffer overflow (CWE-121) in the profile parser of FortiSandbox versions 3.2.2 and below and 3.1.4 and below allows authenticated attackers to execute arbitrary code or commands via specifically crafted HTTP requests.

MitigationUpgrade FortiSandbox to version 3.2.3, 3.1.5, or later. Prior to patching, limit access to authenticated users only and consider network segmentation to reduce exposure.

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
FortisandboxApplication
Affected:>= 3.1.0, <= 3.1.4>= 3.2.0, < 3.2.3= 4.0.0

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
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/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. Check FortiSandbox installed version
    Access FortiSandbox CLI or web UI to retrieve the firmware version. Typically available in the dashboard or via 'get system status' CLI command.
    Affected if Version is 3.1.0 through 3.1.4, 3.2.0 through 3.2.2, or exactly 4.0.0
  2. Confirm web interface accessibility
    Determine if the FortiSandbox HTTP/HTTPS management interface is exposed to network. Check firewall rules or reverse proxy configuration allowing external access to port 443 or 80.
    Affected if Web interface is reachable from untrusted or internet-facing networks
  3. Review remote authentication settings
    Inspect user authentication configuration in FortiSandbox to identify if remote authentication (LDAP, RADIUS, or FortiAuthenticator) is enabled allowing external user logins.
    Affected if Remote authentication is configured and permits access from untrusted networks

Environment is affected if FortiSandbox version matches the vulnerable ranges AND the HTTP interface is accessible to authenticated attackers

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 3.2.3 or later
Fixed in 3.2.3
Interim mitigation

Upgrade FortiSandbox to version 3.2.3, 3.1.5, or later. Prior to patching, limit access to authenticated users only and consider network segmentation to reduce exposure.

Recommended fix High confidence

FortiSandbox 3.2.3 or later; 4.0.1 or later; 3.1.5 or later (if available)

  1. Identify the currently installed FortiSandbox version using the web UI (System > Settings > Firmware) or CLI (get system status)
  2. Download the appropriate fixed firmware version from Fortinet Customer Support portal (https://support.fortinet.com/)
  3. Review Fortinet's release notes for the target firmware version for any migration considerations
  4. Back up the current FortiSandbox configuration
  5. Upload and install the firmware upgrade through the web UI (System > Settings > Firmware > Upload) or CLI
  6. Verify the upgrade was successful and the new version is running
  7. Confirm the vulnerability is resolved by checking the FortiGuard advisory for CVE-2021-26105
Caveat Review release notes for any configuration or behavioral changes between versions; test in non-production environment first

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

Fix this in Fortisandbox Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,580
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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-2021-26105 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