FortiosOperating system · Fortinet
CVE-2019-5588
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 reflected Cross-Site-Scripting (XSS) vulnerability in Fortinet FortiOS 6.0.0 to 6.0.4 under SSL VPN web portal may allow an attacker to execute unauthorized malicious script code via the "err" parameter of the error process 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 confidenceA reflected Cross-Site-Scripting (XSS) vulnerability exists in Fortinet FortiOS SSL VPN web portal versions 6.0.0 through 6.0.4. The vulnerability stems from improper sanitization of the 'err' parameter in error process HTTP requests, allowing attackers to inject malicious script code that executes in the victim's browser when the crafted request is processed.
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
>= 6.0.0, <= 6.0.4CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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.
-
Identify FortiOS versionAccess the SSL VPN login portal or use CLI command 'get system status' to retrieve the FortiOS firmware versionAffected if Version number is 6.0.0, 6.0.1, 6.0.2, 6.0.3, or 6.0.4
-
Confirm SSL VPN web portal is exposedAttempt to access the FortiOS SSL VPN web portal URL (typically /sslvpn/ or /remote/login) in a web browserAffected if The SSL VPN web portal is accessible and responds with a login page
-
Test err parameter for reflected XSSSend a crafted HTTP request to the VPN portal with a test payload in the 'err' parameter, such as '?err=<script>alert(1)</script>' and observe if the payload is reflected unsanitized in the responseAffected if The err parameter value is reflected directly in the HTML response without encoding or sanitization
User is affected if FortiOS version is 6.0.0 through 6.0.4 AND the SSL VPN web portal is accessible AND the err parameter reflects input without sanitization.
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 dataUpdate FortiOS to version 6.0.5 or later. If immediate patching is not possible, implement WAF rules to filter malicious payloads in the 'err' parameter and restrict SSL VPN web portal access to trusted users.
Fix this in Fortios
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-5588 — 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-2019-5588 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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