Security readout for executives and security teams
Plain-English summary
CVE-2019-1964 can let an unauthenticated remote attacker disrupt affected Cisco NX-OS devices by sending malformed IPv6 traffic through them. The immediate impact is service interruption while a network process restarts; sustained attack traffic could reboot the device.
Executive priority
Treat as high priority when affected devices carry important IPv6 traffic or sit in critical network paths. This is an availability risk, not a data theft issue, and the provided evidence does not show active exploitation.
Technical view
Cisco describes improper validation of IPv6 traffic in NX-OS Software. A malformed IPv6 packet sent through an affected device can restart the netstack process, causing denial of service. Sustained exploitation may trigger a device reboot. CVSS 3.0 is 8.6, availability impact only, CWE-20.
Likely exposure
Exposure is most likely on Cisco NX-OS Software 8.1(1) devices that process or forward IPv6 traffic, especially where untrusted traffic can traverse the device. The provided bundle does not identify other affected versions or device models.
Exploitation context
The bundle supports remote, unauthenticated denial of service with low attack complexity. It does not support active exploitation: KEV is false, and no cited source in the bundle states observed exploitation.
Researcher notes
Key gaps are affected version breadth, platform scope, and exact vendor remediation details; the bundle only names Cisco NX-OS Software 8.1(1). Avoid assuming exploit availability, patch levels, or workarounds beyond Cisco’s advisory.
Mitigation direction
- Inventory Cisco NX-OS Software 8.1(1) devices in IPv6 traffic paths.
- Review Cisco’s advisory for fixed releases, workarounds, and platform-specific guidance.
- Prioritize remediation for devices supporting critical network availability.
- Limit untrusted IPv6 traffic paths where operationally feasible.
- Monitor for unexpected netstack restarts and device reboots.
Validation and detection
- Confirm NX-OS version and whether IPv6 traffic passes through each device.
- Review logs and monitoring for netstack restarts or unexplained reboots.
- Check Cisco’s advisory before declaring a device remediated.
- Verify change records for any applied NX-OS upgrade or workaround.
- Document remaining devices where vendor guidance is still pending review.
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-20: 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-2019-1964 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
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
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:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20190828 Cisco NX-OS Software IPv6 Denial of Service 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 Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.