Netscaler Application Delivery Controller FirmwareOperating system · Citrix
CVE-2013-6939
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 · uneditedUnspecified vulnerability in Citrix NetScaler Application Delivery Controller (ADC) 9.3.x before 9.3-64.4, 10.0 before 10.0-77.5, and 10.1 before 10.1-118.7 allows attackers to cause a denial of service via unknown vectors, related to "RADIUS authentication."
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 confidenceDenial of service vulnerability in Citrix NetScaler ADC related to RADIUS authentication processing. Attackers can cause the ADC to become unavailable via unspecified vectors targeting the RADIUS authentication component.
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
Netscaler Application Delivery Controller FirmwareOperating system
= 9.3\(1\)= 9.3.e= 10.0= 10.1CVSS 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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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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Confirm Citrix NetScaler ADC is deployedRun 'show ns version' or access the NetScaler UI to verify the device is a Citrix NetScaler Application Delivery ControllerAffected if The device is not a Citrix NetScaler ADC - this CVE only applies to that specific product
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Check installed firmware versionExecute 'show version' or 'nsversion' at the NetScaler command prompt to retrieve the firmware build numberAffected if The version matches 9.3(1), 9.3.e, 10.0, or 10.1 exactly - note that only these specific versions are affected
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Verify RADIUS authentication is enabledRun 'show radius' or 'show authentication radius' to check if any RADIUS server is configured and enabled on the NetScalerAffected if RADIUS authentication is configured and pointing to a RADIUS server - the vulnerability only triggers when RADIUS processing is active
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Confirm RADIUS authentication policy is boundExecute 'show authentication policy' and check if a RADIUS-based authentication policy is bound to the system (e.g., 'Authentication vServer' or global binding)Affected if A RADIUS authentication policy is actively bound and in use - this is required for the attack vector to be reachable
The system is affected only if it is a Citrix NetScaler ADC running exactly version 9.3(1), 9.3.e, 10.0, or 10.1 AND RADIUS authentication is configured and actively bound.
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 dataUpgrade Citrix NetScaler ADC to version 9.3-64.4, 10.0-77.5, or 10.1-118.7 or later. If RADIUS authentication is not required, consider disabling it until the upgrade can be performed.
Fix this in Netscaler Application Delivery Controller Firmware
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2013-6939 — 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-2013-6939 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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