Security readout for executives and security teams
Plain-English summary
This flaw can let someone within wireless adjacency crash and reload an affected Cisco Catalyst 9000 wireless controller, disrupting service. It does not expose data or allow device takeover in the cited sources, but availability impact can be significant for sites dependent on wireless access.
Executive priority
Treat as high priority where Catalyst 9000 wireless controllers support critical business locations. The main risk is outage, not data theft. Remediation should focus on confirming exposure and following Cisco’s update guidance.
Technical view
CVE-2020-3390 is an input-validation flaw in SNMP trap generation for wireless client connections in Cisco IOS XE Wireless Controller Software for Catalyst 9000. During wireless authentication setup, crafted 802.1x parameters can trigger an unexpected reload, causing denial of service. CVSS 3.0 is 7.4, with adjacent attack vector and high availability impact.
Likely exposure
Exposure is limited to affected Cisco Catalyst 9000 Family deployments running IOS XE Wireless Controller Software with wireless client authentication activity. The supplied bundle does not list specific affected or fixed versions, so asset owners must verify against Cisco’s advisory.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. The attacker must be adjacent and able to interact with the wireless authentication setup path, which narrows exposure compared with internet-facing flaws but remains relevant in campus or branch wireless environments.
Researcher notes
Key technical condition is malformed client data reaching SNMP trap generation during wireless authentication. CWE-20 fits the stated missing input validation. The supplied sources do not provide fixed versions, workarounds, or exploit telemetry beyond KEV being false.
Mitigation direction
- Check Cisco’s advisory for affected and fixed IOS XE releases.
- Prioritize updates for Catalyst 9000 wireless controller deployments.
- Limit wireless authentication attempts to trusted physical and network areas where feasible.
- Monitor controllers for unexpected reloads tied to wireless client activity.
- Review SNMP trap and wireless authentication logging for anomalies.
Validation and detection
- Inventory Catalyst 9000 devices running IOS XE Wireless Controller Software.
- Compare running versions and configuration against Cisco’s advisory.
- Confirm whether wireless client authentication is enabled and in use.
- Review historical reload events during wireless authentication periods.
- Avoid live exploit testing on production controllers.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-3390 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 SNMP Trap Denial of Service VulnerabilityCVE 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.