Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated remote attacker crash affected Cisco wireless controller devices, disrupting wireless service. The business impact is availability, not data theft, but outages on controller infrastructure can affect many users and sites at once.
Executive priority
Treat as high priority where affected controllers support critical wireless access or are reachable from untrusted networks. The main risk is service disruption, potentially across many users, rather than confidentiality or integrity compromise.
Technical view
CVE-2021-1611 affects EoGRE packet processing in Cisco IOS XE Wireless Controller Software for specified Cisco wireless controller deployments. Malformed EoGRE packets can trigger a device reload and denial of service. The CVSS v3.1 score is 8.6, with network access, low complexity, no privileges, and high availability impact.
Likely exposure
Exposure is likely limited to organizations running Cisco IOS XE Wireless Controller Software on Catalyst 9800 Family Wireless Controllers, Embedded Wireless Controller, or Embedded Wireless on Catalyst 9000 Series Switches. The bundle does not provide affected version ranges.
Exploitation context
The bundle states remote unauthenticated exploitation is possible by malicious packets, but does not show active exploitation. CISA KEV status is false, so active exploitation should not be claimed from these sources.
Researcher notes
The source bundle gives product family and attack class but not exact affected versions, fixed releases, or workaround details. Validation should stay focused on advisory matching, EoGRE exposure, and availability telemetry, without assuming broader IOS XE impact.
Mitigation direction
- Review Cisco advisory for fixed releases and official mitigations.
- Prioritize remediation for controllers reachable from untrusted networks.
- Reduce unnecessary network exposure to affected controller services.
- Monitor affected devices for unexpected reloads or wireless outages.
Validation and detection
- Inventory Cisco wireless controllers running IOS XE Wireless Controller Software.
- Compare platforms and releases against Cisco advisory scope.
- Identify whether EoGRE is used or exposed in the deployment.
- Review device logs for unexpected reloads or DoS symptoms.
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-399: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-1611 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
- 8.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/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:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210922 Cisco IOS XE Software for Catalyst 9800 Series Wireless Controllers EoGRE 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.
Resource Management Errors
Resource Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.