Security readout for executives and security teams
Plain-English summary
CVE-2020-3356 is a stored cross-site scripting issue in Cisco Data Center Network Manager. An unauthenticated remote attacker could place malicious content into a log file, which may run in an administrator’s browser when viewed. Business impact is mainly browser-based data exposure or actions in the management interface, not direct system takeover.
Executive priority
Treat this as a moderate-priority management-plane issue. It is not described as actively exploited, but it can affect privileged users of a network management platform and should be remediated through vendor guidance and access control.
Technical view
Cisco describes insufficient input validation in DCNM’s web-based management interface. The CVSS vector is network-accessible, low complexity, no privileges required, user interaction required, changed scope, with low confidentiality and integrity impact and no availability impact. The issue maps to CWE-79.
Likely exposure
Exposure is limited to organizations running Cisco Data Center Network Manager with a reachable web management interface. Risk increases where untrusted users or networks can interact with the interface and administrators later review affected logs.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. Exploitation requires attacker interaction with the interface and a user viewing affected content, so administrative browsing behavior matters.
Researcher notes
Evidence is strongest for vulnerability class, attack prerequisites, and impact from CVE/CVSS data. The bundle does not provide exact affected versions, fixed releases, workaround details, or proof of exploitation, so do not expand claims beyond Cisco DCNM.
Mitigation direction
- Review Cisco’s advisory for affected and fixed DCNM release guidance.
- Restrict DCNM management interface access to trusted administrative networks.
- Prioritize remediation for externally reachable or broadly accessible DCNM interfaces.
- Monitor vendor guidance because exact affected versions are not included in the bundle.
Validation and detection
- Inventory Cisco Data Center Network Manager deployments and ownership.
- Check deployed DCNM versions against Cisco’s advisory.
- Verify whether the web management interface is reachable from untrusted networks.
- Review logs and browser security telemetry for suspicious script-related 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-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-2020-3356 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
- 6.1 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.1MediumVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20200617 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.