FortiosOperating system · Fortinet
CVE-2018-1352
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 · uneditedA format string vulnerability in Fortinet FortiOS 5.6.0 allows attacker to execute unauthorized code or commands via the SSH username variable.
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 · moderate confidenceA format string vulnerability in FortiOS 5.6.0 allows remote attackers to execute arbitrary code or commands via specially crafted format specifiers embedded in the SSH username variable. The lack of input sanitization on the SSH username parameter enables an attacker to overwrite memory and control execution flow.
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
FortiosOperating system
= 5.6.0CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify FortiOS versionExecute 'get system status' or 'get system version' in the FortiOS CLI. Look for the 'Version' field in the output.Affected if The displayed version string shows exactly 5.6.0 (e.g., FortiOS 5.6.0 buildXXXX)
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Confirm SSH service is enabledExecute 'show system interface' in the FortiOS CLI to list interface configurations. Check for 'set ssh-service enable' or verify SSH is listed as an allowed service.Affected if SSH service is enabled on any management interface (port1, mgmt, or dedicated management interface)
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Determine SSH management accessibilityExecute 'show system admin' or 'show system global' to identify which IP addresses or networks are permitted for SSH administrative access. Also check 'get system interface' for the interface IP addresses.Affected if SSH management is bound to an interface reachable from untrusted networks (0.0.0.0/0 or non-restricted subnets)
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Verify external SSH access is permittedReview firewall policy or administrative access settings: run 'get firewall policy' and inspect the 'inspect' or 'set access-service' fields, or check 'show system interface <name>' for 'set allowaccess ssh'.Affected if The SSH service is accessible from external/outside interfaces rather than limited to internal/trusted management networks only
You are affected if your FortiOS version is exactly 5.6.0 AND SSH management interface is enabled and accessible from networks you do not fully control.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataUpgrade FortiOS to the vendor-provided patched version. As an interim control, restrict SSH management access to trusted IPs only or disable external SSH management if not required.
Fix this in Fortios
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-1352 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-1352 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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