Security readout for executives and security teams
Plain-English summary
This issue can let someone on an adjacent network crash and reload an affected Cisco wireless controller. The business impact is wireless service disruption, not data theft. The source bundle does not show active exploitation or specific fixed versions.
Executive priority
Treat this as a high-priority availability risk for enterprise wireless networks using affected Cisco controllers. It is not described as data compromise, but controller reloads can disrupt business operations and user connectivity.
Technical view
CVE-2020-3494 covers insufficient validation of CAPWAP packets in Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers. An unauthenticated adjacent attacker could send a malformed CAPWAP packet and trigger a device crash and reload, causing denial of service. CVSS 3.0 score is 7.4.
Likely exposure
Exposure is most likely in organizations running Cisco Catalyst 9800 Series Wireless Controllers or Catalyst 9000 family wireless controller deployments. The CVSS vector is adjacent network, so exposure depends on who can reach CAPWAP processing paths near the controller.
Exploitation context
The provided sources describe unauthenticated adjacent exploitation with low attack complexity and high availability impact. They do not state public exploitation, weaponized tooling, or inclusion in CISA KEV; the bundle marks KEV as false.
Researcher notes
The vulnerability class is CWE-20 input validation failure in CAPWAP packet handling. Evidence supports adjacent, unauthenticated denial of service only. The source bundle does not provide affected version ranges, proof of exploitation, or detailed remediation text beyond the Cisco advisory reference.
Mitigation direction
- Review Cisco advisory cisco-sa-capwap-dos-TPdNTdyq for affected and fixed release guidance.
- Inventory Cisco Catalyst 9800 Series Wireless Controllers and IOS XE versions.
- Prioritize vendor-recommended updates or workarounds for affected wireless controllers.
- Limit CAPWAP reachability to trusted adjacent network segments where architecture permits.
- Monitor affected controllers for unexpected crashes or reloads until remediated.
Validation and detection
- Confirm whether deployed controllers match Cisco Catalyst 9800 Series Wireless Controller scope.
- Compare installed IOS XE releases against the Cisco advisory.
- Review logs and uptime for crash or reload events affecting wireless availability.
- Verify CAPWAP access paths are limited to expected network segments.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-3494 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.4 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.4HighVector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200924 Cisco IOS XE Wireless Controller Software for the Catalyst 9000 Family CAPWAP Denial of Service VulnerabilitiesCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.