ForticlientApplication · Fortinet
CVE-2017-17543
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 · uneditedUsers' VPN authentication credentials are unsafely encrypted in Fortinet FortiClient for Windows 5.6.0 and below versions, FortiClient for Mac OSX 5.6.0 and below versions and FortiClient SSLVPN Client for Linux 4.4.2335 and below versions, due to the use of a static encryption key and weak encryption algorithms.
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 confidenceFortiClient uses a static encryption key hardcoded in the application binary along with weak encryption algorithms to protect VPN authentication credentials. This allows attackers with access to the encrypted credentials or the application to recover plaintext passwords through cryptanalysis or key extraction.
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
ForticlientApplication
<= 5.6.0
Forticlient Sslvpn ClientApplication
<= 4.4.2335CVSS 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
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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 FortiClient installation and versionCheck the installed FortiClient version using system utilities (e.g., 'Add or Remove Programs' on Windows, dpkg/rpm on Linux, or the application About dialog). Record the full version number.Affected if The installed version is 5.6.0 or earlier for Windows/Mac, or 4.4.2335 or earlier for Linux SSL VPN Client.
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Determine if VPN credentials are storedCheck whether any VPN profiles have been configured with saved passwords or stored authentication credentials in the FortiClient application. Look for saved credential options in VPN profile settings.Affected if VPN profiles exist with saved/stored authentication credentials, as these are protected by the weak encryption mechanism described in the CVE.
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Locate credential storage locationSearch the system for FortiClient configuration or credential files. Typical locations may include user profile directories or application data folders where FortiClient stores VPN profile configurations.Affected if Credential files exist and contain encrypted data, as the hardcoded static key and weak encryption apply to any stored VPN credentials in affected versions.
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Verify encryption implementation (optional)If accessible, examine the FortiClient binary or application files for evidence of hardcoded static encryption keys or known weak cryptographic implementations in the credential storage module.Affected if Static keys or weak encryption algorithms are found in the binary, confirming the vulnerability condition described in the CVE.
A user is affected if FortiClient version is 5.6.0 or earlier (Windows/Mac) or 4.4.2335 or earlier (Linux) AND VPN credentials have been saved/stored in the application.
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 FortiClient to versions above 5.6.0 for Windows/Mac and above 4.4.2335 for Linux, which implement proper dynamic encryption with secure key management.
Fix this in Forticlient
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-17543 — 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-2017-17543 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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- Version or environment caveats, and links to real fixes
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