CVE-2021-1387: high-severity vulnerability in Cisco NX-OS Software
Cisco NX-OS Software IPv6 Netstack Denial of Service Vulnerability
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 1.4%
A vulnerability in the network stack of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because the software improperly releases resources when it processes certain IPv6 packets that are destined to an affected device. An attacker could exploit this vulnerability by sending multiple crafted IPv6 packets to an affected device. A successful exploit could cause the network stack to run out of available buffers, impairing operations of control plane and management plane protocols and resulting in a DoS condition. Manual intervention would be required to restore normal operations on the affected device. For more information about the impact of this vulnerability, see the Details section of this advisory.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected products
Cisco · Cisco NX-OS SoftwareRelated CVEs — Cisco NX-OS Software
In the same product, most dangerous first.
CVE-2024-20399MEDIUMCisco NX-OS Software CLI Command Injection VulnerabilityEPSS 4.3%KEVCVE-2022-20650HIGHCisco NX-OS Software NX-API Command Injection VulnerabilityEPSS 14.5%CVE-2022-20624HIGHCisco NX-OS Software Cisco Fabric Services Over IP Denial of Service VulnerabilityEPSS 12.4%CVE-2022-20623HIGHCisco Nexus 9000 Series Switches Bidirectional Forwarding Detection Denial of Service VulnerabilityEPSS 11.9%CVE-2026-76455CRITICALCisco NX-OS Software Security Hardening Release: October 2026 - Improper Access Control VulnerabilitiesEPSS 3.6%CVE-2022-20625MEDIUMCisco FXOS and NX-OS Software Cisco Discovery Protocol Service Denial of Service VulnerabilityEPSS 3.3%