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Aironet Ap1100Hardware / appliance · Cisco

CVE-2009-2976

HIGH · 7.8 CVSS v2.0 Published 2009-08-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
87/100
Remediation priority · High
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
Cisco Aironet Lightweight Access Point (AP) devices send the contents of certain multicast data frames in cleartext, which allows remote attackers to discover Wireless LAN Controller MAC addresses and IP addresses, and AP configuration details, by sniffing the wireless network.

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

Cisco Aironet Lightweight Access Point devices transmit certain multicast data frames in cleartext without encryption. By sniffing wireless traffic, remote attackers can discover Wireless LAN Controller MAC and IP addresses along with AP configuration details, leading to network reconnaissance and further attacks.

MitigationEnable multicast encryption or upgrade to a firmware version that encrypts multicast traffic. Alternatively, implement network segmentation to isolate multicast traffic and limit exposure of controller information.

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
Aironet Ap1100Hardware / appliance
Affected:all versions
Aironet Ap1200Hardware / appliance
Affected:all versions

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
Complete
Integrity
None
Availability
None

AV:N/AC:L/Au:N/C:C/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 Cisco Aironet AP1100 or AP1200 devices in your network
    Log into your wireless network management system or physically inspect access points to confirm the model numbers. Check your network inventory systems for these specific model designations.
    Affected if You have deployed Cisco Aironet AP1100 or AP1200 access points in your environment.
  2. Verify multicast encryption status on the Wireless LAN Controller
    Access your WLC management interface and navigate to the multicast configuration settings. Look for options related to multicast encryption, such as 'Multicast Encryption' or 'Encrypted Multicast'. Check if this feature is enabled or disabled.
    Affected if Multicast encryption is disabled on the WLC and these AP models are connected to it.
  3. Check AP-level multicast encryption configuration
    Connect to the AP console or management interface and examine the wireless security settings. Look for multicast encryption parameters in the radio configuration or security policies.
    Affected if Multicast encryption is not enabled at the AP level for these specific models.
  4. Capture and analyze wireless multicast traffic
    Use a wireless packet capture tool on the same RF channel as your APs. Filter for multicast frames (destination MAC addresses starting with 01-00-5E or similar) and examine the payload. Verify whether the multicast traffic contents are readable (cleartext) or appear encrypted.
    Affected if Multicast frames are transmitted in cleartext and contain readable WLC MAC addresses, IP addresses, or AP configuration data.

Your environment is affected if you operate Cisco Aironet AP1100 or AP1200 devices with multicast encryption disabled, as evidenced by cleartext multicast frames in wireless captures.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Enable multicast encryption or upgrade to a firmware version that encrypts multicast traffic. Alternatively, implement network segmentation to isolate multicast traffic and limit exposure of controller information.

Fix this in Aironet Ap1100 Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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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-2009-2976 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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