Security readout for executives and security teams
Plain-English summary
CVE-2020-3439 is a stored cross-site scripting flaw in Cisco Data Center Network Manager. An authenticated attacker could place malicious data into a management-interface field, causing script to run in another user's browser. The business risk is compromise of browser-based information or actions within the DCNM interface.
Executive priority
Treat as a moderate-priority management-plane issue. It is not described as actively exploited, but DCNM is operationally sensitive, so confirm exposure and vendor remediation status during normal vulnerability cycles.
Technical view
Cisco describes insufficient input validation in the DCNM web-based management interface. The CVSS 3.0 score is 5.9, with network access, low attack complexity, high privileges, required user interaction, and changed scope. CWE-79 applies.
Likely exposure
Exposure is limited to organizations running Cisco Data Center Network Manager with its web management interface accessible to authenticated users. The provided bundle does not identify exact affected versions or deployment modes.
Exploitation context
No KEV listing is provided, and the source bundle does not cite active exploitation. Exploitation requires authenticated access and user interaction, but successful stored XSS could affect another interface user within the DCNM browser context.
Researcher notes
The provided evidence confirms stored XSS mechanics, CVSS vector, affected product, and vendor advisory. It does not include exact vulnerable versions, fixed versions, or workaround details, so those must come from Cisco's advisory before closure.
Mitigation direction
- Review Cisco's advisory for affected and fixed DCNM releases.
- Apply Cisco-recommended updates or workarounds when identified.
- Restrict DCNM management interface access to trusted administrative networks.
- Remove unnecessary DCNM accounts and excessive privileges.
- Monitor Cisco advisories for version-specific remediation details.
Validation and detection
- Inventory all Cisco DCNM deployments and exposed management interfaces.
- Confirm installed DCNM versions against Cisco's advisory.
- Review which authenticated users can access the vulnerable interface.
- Check logs for suspicious stored content or unusual interface activity.
- Verify remediation after applying Cisco 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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2020-3439 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
- 5.9 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
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:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L1.73.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.9MediumVector: CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- 20200819 Cisco Data Center Network Manager Stored Cross-Site Scripting 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 Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.