CVE-2021-20019
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 vulnerability in SonicOS where the HTTP server response leaks partial memory by sending a crafted HTTP request, this can potentially lead to an internal sensitive data disclosure vulnerability.
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 confidenceA memory disclosure vulnerability exists in the SonicOS HTTP server component. An unauthenticated remote attacker can send a specially crafted HTTP request to cause the server to leak partial memory contents in its HTTP response, potentially exposing sensitive internal data.
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>= 7.0.0, < 7.0.0.376>= 7.0.1, < 7.0.1-r1036= 6.0.5.3-94o= 6.5.1.12-3n= 6.5.4.7-83n= 6.5.4.4-44v-21-955CVSS 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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Identify the SonicOS versionAccess the device management interface and navigate to System > Status or use the CLI command 'show version' to display the installed SonicOS version and build numberAffected if The displayed version falls within any of these ranges: 7.0.0 through 7.0.0.375, 7.0.1 through 7.0.1-r1035, exactly 6.0.5.3-94o, exactly 6.5.1.12-3n, exactly 6.5.4.7-83n, or exactly 6.5.4.4-44v-21-955 (Sonicosv)
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Verify HTTP management interface is enabledCheck the device network settings to confirm the HTTP server component is listening on any accessible interface. In the management GUI, go to Network > Interfaces and verify HTTP management is enabled on the relevant zone or interfaceAffected if HTTP management interface is enabled and reachable on the device
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Check if HTTP is exposed to untrusted networksReview firewall access rules and interface bindings to determine if the SonicWall management HTTP port (typically port 80 or 443) is exposed to external or untrusted networks rather than being restricted to trusted management networksAffected if The HTTP management interface is accessible from external or untrusted network segments
The device is affected if it runs any SonicOS version within the vulnerable ranges listed and has its HTTP management interface exposed, making it possible for an unauthenticated attacker to send crafted requests that leak memory contents.
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 data7.0.0.3767.0.1-r1036
Apply the vendor-supplied SonicOS patch for CVE-2021-20019. If immediate patching is not possible, restrict or block untrusted HTTP access to the affected SonicWall device management interfaces from external networks.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20019 — 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-2021-20019 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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