Security readout for executives and security teams
Plain-English summary
CVE-2021-1127 is a stored cross-site scripting issue in Cisco Enterprise NFV Infrastructure Software. A logged-in attacker could place malicious content into a device log and persuade another interface user to view it. The impact is browser-side: script execution in the management interface context or access to sensitive browser-based information.
Executive priority
Treat this as a moderate-priority management-plane issue. It is unlikely to drive emergency response by itself, but it affects administrative trust boundaries and should be remediated during normal vulnerability maintenance, especially for internet-reachable or broadly accessible management interfaces.
Technical view
The flaw is CWE-79 in the NFVIS web-based management interface. Cisco attributes it to improper input validation of stored log file content. Exploitation requires network access, low privileges, and user interaction. Scope changes because script runs in another user’s browser context, with limited confidentiality and integrity impact and no availability impact in the CVSS vector.
Likely exposure
Exposure is limited to environments running Cisco Enterprise NFV Infrastructure Software with reachable web management interfaces. Risk is higher where lower-privileged authenticated users can influence logs and where administrators routinely review logs through the same interface.
Exploitation context
The source bundle does not show known active exploitation, and the CVE is not marked KEV. Exploitation is not unauthenticated; it requires an authenticated attacker and a user viewing the modified log file in the web interface.
Researcher notes
Evidence is strongest for vulnerability class, attack preconditions, and impact from the CVE and Cisco advisory metadata. The provided affected version data is incomplete, listed as n/a, so version-specific exposure and fixed-release confirmation require Cisco advisory review.
Mitigation direction
- Review Cisco’s advisory for affected and fixed NFVIS release guidance.
- Restrict NFVIS web management access to trusted administrative networks.
- Limit NFVIS accounts to required roles and remove unnecessary access.
- Monitor Cisco guidance for any updated remediation or workaround details.
Validation and detection
- Inventory Cisco Enterprise NFV Infrastructure Software deployments.
- Compare deployed NFVIS versions against Cisco’s advisory guidance.
- Confirm management interfaces are not broadly reachable.
- Review account permissions for users who can influence or review logs.
- Check security monitoring for suspicious management-interface 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-2021-1127 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
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/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:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210113 Cisco Enterprise NFV Infrastructure Software 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.