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Nac Guest ServerHardware / appliance · Cisco

CVE-2011-0963

MEDIUM · 5.0 CVSS v2.0 Published 2011-03-31
Fix available
A fix is available. Upgrade to after 2.0.2 or later.
See remediation →
59/100
Remediation priority · Elevated
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
The default configuration of the RADIUS authentication feature on the Cisco Network Admission Control (NAC) Guest Server with software before 2.0.3 allows remote attackers to bypass intended access restrictions and obtain network connectivity via unspecified vectors, aka Bug ID CSCtj66922.

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 confidence

The Cisco NAC Guest Server versions before 2.0.3 have an insecure default configuration in the RADIUS authentication feature that allows remote attackers to bypass intended access restrictions and obtain unauthorized network connectivity.

MitigationUpgrade Cisco NAC Guest Server to version 2.0.3 or later, or review and harden the RADIUS authentication configuration to ensure proper access controls are enforced.

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
Nac Guest ServerHardware / appliance
Affected:all versions
Nac Guest Server SoftwareApplication
Affected:<= 2.0.2= 1.0.0= 1.1.0= 1.1.1= 1.1.2= 1.1.3= 2.0.0= 2.0.1

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
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None

AV:N/AC:L/Au:N/C:P/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 checks

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

  1. Identify installed Cisco NAC Guest Server version
    Access the admin console or use the command line interface to display the software version. Look for a version display command such as 'show version' or check the About/Status page in the web interface.
    Affected if The installed version is 1.0.0, 1.1.0, 1.1.1, 1.1.2, 1.1.3, 2.0.0, 2.0.1, or any version prior to 2.0.3 (versions <= 2.0.2).
  2. Verify RADIUS authentication feature is enabled
    Navigate to the NAC Guest Server administration interface and locate the RADIUS authentication settings under the authentication or network access configuration section. Confirm the RADIUS service is active and configured.
    Affected if RADIUS authentication is enabled and connected to a RADIUS server for network access control.
  3. Inspect RADIUS access control configuration
    Review the RADIUS authentication policy settings to determine whether guest users or unauthenticated devices are permitted to access the network by default. Check for any 'permit guest access' or 'allow unauthenticated' settings that may be enabled.
    Affected if The RADIUS configuration contains default or permissive access rules that allow unauthenticated or unauthorized users to obtain network connectivity without proper credentials.
  4. Check for default RADIUS shared secret
    Examine the RADIUS client configuration to verify if the default shared secret (often a well-known or factory default value) is still in use rather than a custom, strong secret.
    Affected if A default or weak RADIUS shared secret is configured, which could facilitate unauthorized RADIUS server impersonation.
  5. Review guest access authorization policies
    Look for any guest authorization profiles or policies that grant network access privileges without requiring full authentication completion or proper access control validation.
    Affected if Guest users can bypass intended access restrictions and obtain network connectivity through default authorization settings.

You are affected if your Cisco NAC Guest Server software version is 2.0.2 or earlier (including 1.0.0 through 2.0.1) AND the RADIUS authentication feature is configured with default settings that permit unauthenticated or unauthorized network access.

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
Upgrade available Upgrade to a release after 2.0.2
Interim mitigation

Upgrade Cisco NAC Guest Server to version 2.0.3 or later, or review and harden the RADIUS authentication configuration to ensure proper access controls are enforced.

Fix this in Nac Guest Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,140
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Scan for this in your stack

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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-2011-0963 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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