Security readout for executives and security teams
Plain-English summary
This issue lets a highly privileged administrator on an affected Cisco Nexus 9000 ACI-mode switch read files they should not access. It is not a remote break-in path, but it can expose sensitive device data if an admin account is misused or compromised.
Executive priority
Treat this as a controlled-priority infrastructure fix. It is not remotely exploitable from the supplied evidence, but affected core switching infrastructure and high-confidentiality file access justify timely validation, upgrade planning, and privileged-access review.
Technical view
Cisco describes improper access control in the fabric infrastructure file system controls of Nexus 9000 Series switches running NX-OS System Software in ACI mode. A local authenticated attacker with Administrator privileges could invoke vulnerable functionality and read arbitrary files. Impact is confidentiality only in the supplied CVSS vector.
Likely exposure
Exposure is likely limited to organizations operating Cisco Nexus 9000 fabric switches in ACI mode. The attacker needs local authenticated Administrator privileges, so risk depends heavily on admin account control, device access paths, and privileged session monitoring.
Exploitation context
The supplied bundle does not show CISA KEV listing or other evidence of active exploitation. Exploitation requires Administrator privileges on the affected device, making compromised admin credentials, insider misuse, or weak privileged-access governance the main concern.
Researcher notes
Evidence is limited to the CVE and Cisco advisory metadata in the bundle. Affected versions are not enumerated here. The CVSS vector is AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N, aligned with CWE-284 improper access control.
Mitigation direction
- Inventory Cisco Nexus 9000 switches running ACI mode.
- Review Cisco’s advisory for affected and fixed software guidance.
- Restrict Administrator access to trusted operators only.
- Audit privileged accounts and remove stale access.
- Monitor administrative activity for unusual file access behavior.
Validation and detection
- Confirm whether deployed Nexus 9000 switches run ACI mode.
- Compare installed NX-OS versions with Cisco advisory guidance.
- Review Administrator account membership and recent changes.
- Check device administration logs for unusual privileged activity.
- Verify upgrade or mitigation status in change records.
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-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-1583 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
- 4.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/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:N/A:N0.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.4MediumVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210825 Cisco Nexus 9000 Series Fabric Switches ACI Mode Arbitrary File Read 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 Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.