Security readout for executives and security teams
Plain-English summary
CVE-2021-1584 lets a highly privileged local administrator on Cisco Nexus 9000 switches in ACI mode escalate to root on the underlying operating system. It is not remotely reachable by unauthenticated attackers, but it can deepen compromise if an admin account or management path is abused.
Executive priority
Treat as a controlled but meaningful infrastructure risk. It is not a broad internet-facing emergency, but root access on fabric switches is high impact. Prioritize remediation where ACI management access is shared, weakly monitored, or reachable from broader networks.
Technical view
Cisco describes insufficient restrictions around a specific CLI command, enabling command injection by an authenticated local attacker with administrative privileges. Successful exploitation can provide root access to the underlying OS. The issue maps to CWE-78 and has CVSS 3.1 score 6.0.
Likely exposure
Exposure is limited to Cisco Nexus 9000 Series fabric switches running Cisco NX-OS System Software in ACI mode. Organizations without Nexus 9000 ACI deployments are not indicated as affected by the supplied sources.
Exploitation context
The supplied sources do not show CISA KEV listing or active exploitation. Exploitation requires local authenticated administrative privileges, so the main concern is insider misuse or escalation after compromise of an admin account.
Researcher notes
Key constraints are AV:L and PR:H, with high confidentiality and integrity impact but no availability impact in the CVSS vector. The public bundle does not provide exploit procedures or fixed-release details; rely on Cisco’s advisory for exact remediation mapping.
Mitigation direction
- Review Cisco advisory for affected and fixed NX-OS ACI releases before scheduling maintenance.
- Upgrade affected Nexus 9000 ACI switches according to Cisco guidance.
- Limit administrative CLI access to trusted operators and management networks.
- Review administrative account access and remove unnecessary high-privilege users.
Validation and detection
- Inventory Nexus 9000 switches and confirm which run NX-OS in ACI mode.
- Compare installed software releases with Cisco advisory guidance.
- Confirm administrative access is restricted and logged.
- Review device audit logs for unusual privileged CLI activity.
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-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-1584 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
- Medium
- CVSS
- 6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
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:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N0.85.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6MediumVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210825 Cisco Nexus 9000 Series Fabric Switches ACI Mode Privilege Escalation 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 Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.