Usg9500 FirmwareOperating system · Huawei

CVE-2019-5275

HIGH · 7.5 CVSS v3.1 Published 2019-12-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
USG9500 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 a heap buffer overflow when decoding a certificate, an attacker may exploit the vulnerability by 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 · high confidence

Heap buffer overflow vulnerability in the X.509 certificate decoding implementation of Huawei USG9500 firewalls (V500R001C30 and V500R001C60). An attacker can exploit this by presenting a specially crafted malicious X.509 certificate, triggering a heap buffer overflow that causes denial of service.

MitigationApply vendor-supplied firmware patches to update USG9500 to a patched version. Until patch is available, consider implementing certificate validation/filtering at upstream devices or restricting certificate acceptance to trusted CAs only.

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
Usg9500 FirmwareOperating system
Affected:= v500r001c30= v500r001c60

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the device model
    Log into the USG9500 firewall and run 'display device information' or check the device label/model to confirm it is a Huawei USG9500 series firewall
    Affected if Device is not a USG9500 model (not affected)
  2. Check the firmware version
    Run 'display version' or check the firmware version through the device management interface. Look for version numbers V500R001C30 or V500R001C60
    Affected if Firmware version is exactly V500R001C30 or V500R001C60 (these are the affected versions)
  3. Verify X.509 certificate processing is in use
    Check if the firewall is configured to process or validate X.509 certificates. Look for SSL VPN, IPsec VPN, or SSL inspection configurations that involve certificate handling. Run 'display ssl vpn' or 'display ipsec sa' to see active certificate-based tunnels
    Affected if X.509 certificate processing is enabled and the device accepts/processing external certificates (required for exploit vector)
  4. Check for certificate-related services
    Review the device configuration for any features that decode or parse X.509 certificates, such as 'display ssl policy' or examine CA certificate imports
    Affected if Certificate decoding features are configured on the device

The device is affected if it is a USG9500 running firmware V500R001C30 or V500R001C60 AND has X.509 certificate processing or certificate-based VPN/SSL inspection features enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-supplied firmware patches to update USG9500 to a patched version. Until patch is available, consider implementing certificate validation/filtering at upstream devices or restricting certificate acceptance to trusted CAs only.

Fix this in Usg9500 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-5275 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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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