Security readout for executives and security teams
Plain-English summary
Cisco DCNM had certificate validation flaws that could let an attacker impersonate a trusted host or intercept HTTPS traffic. The business risk is unauthorized alteration of some API requests and possible exposure of sensitive information in data center network management workflows.
Executive priority
Treat as high priority if Cisco DCNM manages production data center networks. Integrity impact against management APIs can create operational risk even without confirmed exploitation.
Technical view
CVE-2021-1277 covers multiple CWE-295 issues in Cisco Data Center Network Manager. Insufficient certificate validation during HTTPS requests could enable trusted-host spoofing or man-in-the-middle positioning. CVSS 3.1 is 7.5, network-accessible, low complexity, no privileges or user interaction required, with high integrity impact.
Likely exposure
Exposure is limited to organizations running Cisco Data Center Network Manager. The provided source bundle does not identify specific affected or fixed versions, so teams must map deployed DCNM versions against Cisco’s advisory.
Exploitation context
The source bundle does not report active exploitation, and the CVE is not marked KEV. The described attack requires a network position enabling host spoofing or man-in-the-middle interference with DCNM HTTPS requests.
Researcher notes
The bundle confirms the vulnerability class, product, impact pattern, CVSS vector, and vendor advisory reference, but not version ranges or fixed releases. Avoid assuming exploit availability or specific remediation beyond Cisco guidance.
Mitigation direction
- Inventory Cisco DCNM deployments and identify installed versions.
- Review Cisco’s advisory for affected releases and vendor-approved fixes.
- Apply Cisco-recommended fixed software or mitigations where applicable.
- Restrict DCNM management access to trusted administrative paths while assessing exposure.
Validation and detection
- Confirm whether Cisco Data Center Network Manager is deployed.
- Compare installed DCNM versions with Cisco’s advisory details.
- Review DCNM API change history for unexpected or unauthorized alterations.
- Validate certificate handling against Cisco-supported configuration guidance.
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-2021-1277 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.