CVE-2019-5274
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 · uneditedUSG9500 with versions of V500R001C30;V500R001C60 have a denial of service vulnerability. Due to a flaw in the X.509 implementation in the affected products which can result in an infinite loop, an attacker may exploit the vulnerability via a malicious certificate to perform a denial of service attack on the affected products.
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 confidenceThe vulnerability exists in the X.509 certificate parsing implementation on Huawei USG9500 firewalls running V500R001C30 or V500R001C60. A specially crafted or malformed X.509 certificate can trigger an infinite loop during certificate processing, causing the device to become unresponsive and resulting in a denial of service condition.
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= v500r001c30= v500r001c60CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 device modelRun 'display device' or 'display version' command on the device CLI to confirm the hardware model is USG9500Affected if Device is not a USG9500 model - this CVE only applies to USG9500 firewalls
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Check firmware versionRun 'display version' or check the system banner to identify the installed firmware versionAffected if Version is exactly V500R001C30 or V500R001C60 - only these two versions are affected
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Verify X.509 certificate processing is enabledCheck device configuration for SSL VPN, IPsec VPN, or other features that process X.509 certificates using 'display current-configuration' or 'display ssl vpn' commandsAffected if Certificate processing features such as SSL VPN, IPsec VPN with certificate authentication, or SSL inspection are configured and active on the device
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Check for device unresponsiveness symptomsMonitor for device becoming unresponsive, high CPU usage, or certificate-related service failures; check logs for parsing errors or loop conditionsAffected if Device exhibits hangs, unresponsiveness, or certificate processing failures after handling malformed X.509 certificates
You are affected if you are running a USG9500 with firmware V500R001C30 or V500R001C60 and have certificate processing features (SSL VPN, IPsec with certificates, SSL inspection) enabled on the device.
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 dataApply vendor-supplied patches or firmware updates to resolve the X.509 parsing flaw. Until patches are available, consider implementing certificate validation/filtering at network boundaries to reject malformed certificates before they reach affected USG9500 devices.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2019-5274 — 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-2019-5274 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
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