Ios XeOperating system · Cisco
CVE-2020-3429
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 · uneditedA vulnerability in the WPA2 and WPA3 security implementation of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9000 Family could allow an unauthenticated, adjacent attacker to cause denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect packet processing during the WPA2 and WPA3 authentication handshake when configured for dot1x or pre-shared key (PSK) authentication key management (AKM) with 802.11r BSS Fast Transition (FT) enabled. An attacker could exploit this vulnerability by sending a crafted authentication packet to an affected device. A successful exploit could cause an affected device to reload, resulting in a DoS condition.
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 confidenceA vulnerability in the WPA2 and WPA3 implementation of Cisco IOS XE Wireless Controller Software for Catalyst 9000 Family allows an unauthenticated, adjacent attacker to cause device reload (DoS) by sending a crafted authentication packet. The flaw exists in packet processing during WPA2/WPA3 handshake when configured with dot1x or PSK AKM and 802.11r BSS Fast Transition (FT) enabled.
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
Ios XeOperating system
= 16.12.1sCVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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 Cisco IOS XE versionRun 'show version' on the device CLI and locate the IOS XE version number in the outputAffected if The version matches 16.12.1s or falls within the affected version range
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Confirm wireless controller is in useRun 'show wireless summary' or 'show controller' to verify the device has Wireless Controller functionality enabledAffected if Wireless Controller Software for Catalyst 9000 Family is active
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Verify 802.11r BSS Fast Transition is enabledRun 'show wireless mobility summary' or 'show run | include ft' to check if Fast Transition is configured on WLANs or wireless profilesAffected if 802.11r BSS Fast Transition is enabled in the wireless configuration
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Check wireless security AKM modeRun 'show wlan summary' and 'show wlan id <num>' to view WLAN security settings, looking for dot1x or PSK authentication key managementAffected if WLAN is configured with dot1x or PSK AKM mode
A device is affected if it runs a vulnerable IOS XE version AND has wireless controller enabled AND uses dot1x or PSK AKM AND has 802.11r BSS Fast Transition simultaneously configured.
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 dataEither update to a patched Cisco IOS XE version, or if 802.11r FT is not required, disable BSS Fast Transition in the wireless controller configuration as an interim workaround.
Fix this in Ios Xe
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3429 — 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-2020-3429 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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