FortiosOperating system · Fortinet
CVE-2019-15703
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 · uneditedAn Insufficient Entropy in PRNG vulnerability in Fortinet FortiOS 6.2.1, 6.2.0, 6.0.8 and below for device not enable hardware TRNG token and models not support builtin TRNG seed allows attacker to theoretically recover the long term ECDSA secret in a TLS client with a RSA handshake and mutual ECDSA authentication via the help of flush+reload side channel attacks in FortiGate VM models only.
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 confidenceInsufficient entropy in FortiOS PRNG allows recovery of ECDSA private keys via flush+reload side-channel attacks. The vulnerability affects FortiGate VM models running FortiOS 6.2.1, 6.2.0, 6.0.8 and below when hardware TRNG is not enabled or the model lacks builtin TRNG seed support. Attack requires RSA handshake with mutual ECDSA authentication.
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
<= 5.6.9>= 6.0.0, < 6.0.9>= 6.2.0, < 6.2.3CVSS 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:3.1/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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Check FortiOS versionRun `get system status` in FortiOS CLI or check System > Firmware in GUI. Look for the Version field.Affected if Version is <= 5.6.9, or >= 6.0.0 and < 6.0.9, or >= 6.2.0 and < 6.2.3
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Confirm FortiGate model typeRun `get system status` and check the Model field, or inspect the hardware serial number format. VM models typically have virtual hardware serial numbers.Affected if Device is a FortiGate VM model (virtual appliance)
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Verify if hardware TRNG is enabledRun `get hardware hardware` or check System > Settings in GUI for hardware random number generator (TRNG/hardware entropy) status. On VM models, check if TRNG passthrough or hardware entropy source is configured.Affected if Hardware TRNG is NOT enabled or the model lacks builtin TRNG seed support (common on VM models)
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Check if mutual ECDSA authentication is in useReview SSL VPN, SSL inspection, or IPsec configuration for ECDSA certificate usage in mutual authentication. Check with `show vpn ssl settings` or review certificate profiles.Affected if Mutual ECDSA authentication is configured for SSL VPN, SSL inspection, or IPsec tunnels
User is affected if running a vulnerable FortiOS version on a VM model without hardware TRNG enabled and with mutual ECDSA authentication configured.
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 data6.0.96.2.3
Enable hardware TRNG token or upgrade to patched FortiOS version. For VM models, ensure proper entropy source configuration is implemented.
Fix this in Fortios
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-15703 — 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-2019-15703 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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- 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
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