Security readout for executives and security teams
Plain-English summary
Cisco Data Center Network Manager may not properly validate HTTPS certificates. An attacker could impersonate a trusted host or intercept traffic, potentially changing API requests or exposing sensitive information. This is a high-priority integrity risk for environments using Cisco DCNM.
Executive priority
Prioritize this where DCNM supports production data center operations. The main risk is unauthorized alteration of management API requests, which can undermine network integrity even without reported active exploitation.
Technical view
CVE-2021-1276 is a CWE-295 certificate validation flaw in Cisco DCNM. The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N, scoring 7.5. The source bundle does not provide affected version ranges or fixed release details.
Likely exposure
Exposure is limited to organizations running Cisco Data Center Network Manager. Version-specific impact cannot be determined from the provided bundle, so asset owners should verify their DCNM releases against Cisco’s advisory.
Exploitation context
The provided sources do not show CISA KEV listing or other evidence of active exploitation. The described attack scenario involves network-based spoofing or man-in-the-middle positioning against HTTPS trust validation.
Researcher notes
Evidence is limited to the CVE metadata and Cisco advisory reference in the bundle. Do not assume specific vulnerable versions, public exploit availability, or remediation details beyond Cisco guidance without reviewing the advisory.
Mitigation direction
- Review Cisco’s advisory for affected and fixed DCNM releases.
- Upgrade or patch DCNM according to Cisco’s published guidance.
- Limit network paths that can reach DCNM management interfaces.
- Monitor DCNM-related HTTPS and API activity for unexpected endpoints.
- Treat unverified certificates or trust changes as security events.
Validation and detection
- Inventory all Cisco Data Center Network Manager deployments.
- Confirm each DCNM version against Cisco’s advisory.
- Review DCNM HTTPS certificate trust configuration and recent changes.
- Check logs for unexpected API request changes or unusual peer hosts.
- Document compensating controls where patch status is unresolved.
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-295: 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-2021-1276 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210120 Cisco Data Center Network Manager Certificate Validation 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 Certificate Validation
Improper Certificate Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.