CVE-2020-5132
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 · uneditedSonicWall SSL-VPN products and SonicWall firewall SSL-VPN feature misconfiguration leads to possible DNS flaw known as domain name collision vulnerability. When the users publicly display their organization’s internal domain names in the SSL-VPN authentication page, an attacker with knowledge of internal domain names can potentially take advantage of this 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 confidenceSonicWall SSL-VPN products contain a misconfiguration where internal domain names are displayed on the publicly accessible VPN authentication page. This creates a domain name collision vulnerability where an attacker with knowledge of the organization's internal domain names can potentially manipulate DNS resolution or intercept authentication traffic.
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= 10.2.0.2-20sv= 12.4.0-2223= 6.5.4.6-79nCVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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 SonicWall SSL-VPN product and versionAccess the SSL-VPN portal URL (typically /sslvpn or /gateway on port 443) or check the device admin interface for the firmware version under System > Status or Device > FirmwareAffected if The device is a SonicWall SMA100 or Sonicos product running version 10.2.0.2-20sv, 12.4.0-2223, or 6.5.4.6-79n
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Examine the SSL-VPN login page for internal domain namesLoad the public SSL-VPN login page in a web browser and inspect the page source (View > Page Source) or look for any domain names displayed in the login form, error messages, or connection settingsAffected if Any internal or private domain names (such as corp.example.com, internal.company.local, or similar) are visible on the publicly accessible VPN login page
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Check SSL-VPN domain configuration settingsLog into the SonicWall admin interface and navigate to SSL-VPN > Client Settings or SSL-VPN > Server Settings. Look for any settings that control domain name display, realm configuration, or login page contentAffected if The SSL-VPN is configured to display or transmit internal domain names to the login page, or proper domain isolation settings are not enabled
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Verify DNS resolution behavior from VPN clientConnect to the VPN (if permitted) or review the VPN client configuration file. Observe whether the internal domain names seen on the login page match the organization's actual internal DNS namespaceAffected if The domain names exposed on the login page match the organization's internal Active Directory or DNS domain names, indicating a namespace collision risk
A user is affected if their publicly accessible SonicWall SSL-VPN login page displays internal domain names, regardless of the firmware version, as this creates the domain name collision vulnerability described in this CVE.
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 dataOrganizations should configure the SSL-VPN to not expose internal domain names on the login page and implement proper DNS namespace isolation to prevent domain name collision attacks.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-5132 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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