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CVE Record

CVE-2019-1968: Cisco NX-OS Software NX-API Denial of Service Vulnerability

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to unexpectedly restart. The vulnerability is due to incorrect validation of the HTTP header of a request that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API on an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition in the NX-API service; however, the NX-OS device itself would still be available and passing network traffic. Note: The NX-API feature is disabled by default.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2019-1968 can let an unauthenticated remote attacker disrupt Cisco NX-OS NX-API service availability by triggering an unexpected process restart. The switch itself should continue forwarding network traffic. Business impact is mainly loss or instability of API-based management, automation, or monitoring, and exposure is lower because NX-API is disabled by default.

Executive priority

Treat this as a moderate operational risk. It is unlikely to stop packet forwarding, but it can disrupt API-based administration and automation. Prioritize exposed management planes and environments dependent on NX-API workflows.

Technical view

The issue is incorrect HTTP header validation in the NX-API feature of Cisco NX-OS Software. A crafted HTTP request to NX-API can restart an NX-API system process, causing denial of service for that service only. The supplied affected entry names Cisco NX-OS Software 6.0(2)A4(1). CVSS is 5.3, network exploitable, unauthenticated, low availability impact.

Likely exposure

Exposure is limited to Cisco NX-OS devices where NX-API is enabled and reachable. Devices using the default disabled NX-API state are not exposed through this feature. The provided bundle identifies Cisco NX-OS Software 6.0(2)A4(1), but broader version details require Cisco advisory review.

Exploitation context

The bundle does not indicate known active exploitation, and KEV status is false. Exploitation requires network reachability to NX-API, but no credentials or user interaction. The result is NX-API service denial of service, not device traffic forwarding failure.

Researcher notes

Evidence supports unauthenticated network-triggered NX-API process restart due to CWE-20 input validation failure. Do not assume compromise of confidentiality, integrity, or switch forwarding. Version scope and exact remediation details are incomplete in the supplied bundle beyond the Cisco advisory reference.

Mitigation direction

  • Confirm NX-API remains disabled where it is not operationally required.
  • Review the Cisco advisory for fixed releases or official workarounds.
  • Prioritize remediation for internet-facing or broadly reachable management interfaces.
  • Monitor NX-API process stability until remediation is complete.

Validation and detection

  • Inventory Cisco NX-OS devices and identify any running 6.0(2)A4(1).
  • Check whether NX-API is enabled on each potentially affected device.
  • Confirm NX-API is reachable only from intended management networks.
  • Review device logs for unexpected NX-API process restarts.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-20: Exact CWE lookup

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cve · low confidence lookup

CVE-2019-1968 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.3 (3.0)
Known Exploited
No
Published

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
5.3CVSS 3.0MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

5.3Medium
CVSS 3.0 vector shape for CVE-2019-1968Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco NX-OS Software 6.0(2)A4(1)unspecifiedListed
Weakness

CWE details

CWE-20

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.