CVE-2020-8430
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 · uneditedStormshield Network Security 310 3.7.10 devices have an auth/lang.html?rurl= Open Redirect vulnerability on the captive portal. For example, the attacker can use rurl=//example.com instead of rurl=https://example.com in the query string.
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 confidenceStormshield Network Security 310 devices running version 3.7.10 contain an open redirect vulnerability in the captive portal's authentication page (auth/lang.html). The rurl parameter accepts arbitrary values without proper validation, allowing attackers to redirect users to malicious sites by supplying protocols like '//example.com' instead of 'https://example.com'. This enables phishing attacks by leveraging the trusted domain appearance.
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>= 3.0.0, <= 3.7.10>= 3.8.0, <= 3.10.0>= 4.0.0, <= 4.0.1CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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 installed Stormshield firmware versionAccess the device CLI or web interface and retrieve the firmware version from system information or use the command 'nsdp -v' or check the about page in the web management consoleAffected if The installed version falls within any of these ranges: 3.0.0 to 3.7.10, 3.8.0 to 3.10.0, or 4.0.0 to 4.0.1
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Confirm the captive portal feature is enabledIn the Stormshield web interface, navigate to the captive portal configuration section or check the authentication settings to verify the captive portal is activeAffected if The captive portal feature is enabled on the device
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Locate the vulnerable authentication pageAccess the URL path /auth/lang.html on the Stormshield device, which serves the captive portal authentication pageAffected if The device responds with the captive portal login page at this path
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Test the rurl parameter for open redirect behaviorSubmit a request to auth/lang.html with an rurl parameter set to an external domain such as '//example.com' and observe if the device allows the redirect without sanitizationAffected if The rurl parameter accepts arbitrary values and the device redirects to the specified external URL without proper validation
The device is affected if it runs a version within 3.0.0-3.7.10, 3.8.0-3.10.0, or 4.0.0-4.0.1 AND has the captive portal enabled, allowing the rurl parameter to redirect users to external domains.
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 dataImplement strict validation of the rurl parameter to ensure only whitelisted internal domains are allowed for redirects. The fix should reject any rurl values containing external domains or non-https protocols.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-8430 — 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-2020-8430 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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