CVE-2021-1387 Cisco NX-OS
| Affected software | Cisco NX-OS |
|---|---|
| Severity | 8.6 High CVSS 3.1 3 scores |
| Weakness | CWE-401 |
| Published | 24 Feb 2021 |
| Updated | 17 Jun 2026 |
Description
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.
Exploitation status
No public exploit
No exploit has been reported in the sources we check. Published 5 years ago.
Exploitation status
- CISA KEV not listed
- VulnCheck KEV not listed
- CISA Vulnrichment no assessment published
- Indexed PoC none indexed
- EPSS 1.4% chance in 30 days
Waratek protection
A Java vulnerability, but not one Waratek protects. It affects only Java on a user's desktop (applets, Web Start, JavaFX, the installer), sits in a product the Waratek agent can't be installed into, or is in a package we don't expect in business applications. The decision below says which.
- Protection none
- Action not pursued none
- Review human Researcher
- Record active
| Decided by | Manual classification of this CVE in the legacy dataset |
|---|---|
| Finding | A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product. |
CVSS
8.6 HIGH
v3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
3 metrics
CVSS
8.6 HIGH v3.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
3 metrics
We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.
| Version | Score | Band | Vector | Assigner | Type | |
|---|---|---|---|---|---|---|
| CVSS 3.1 | 8.6 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
psirt@cisco.com | Secondary | published |
| CVSS 3.1 | 8.6 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
NVD | Primary | |
| CVSS 2.0 | 4.3 | none | AV:N/AC:M/Au:N/C:N/I:N/A:P |
NVD | Primary |
Affected software and releases
Products and versions
2 products, 241 version entries| Source | Vendor | Product | Scheme | Affected versions |
|---|---|---|---|---|
| nvd | cisco | nx-os | generic | 6.0\(2\)u2\(1\) · 6.0\(2\)u2\(2\) · 6.0\(2\)u2\(3\) · 6.0\(2\)u2\(4\) · 6.0\(2\)u2\(5\) · 6.0\(2\)u2\(6\) · 6.0\(2\)a3\(1\) · 6.0\(2\)u3\(1\) · 6.0\(2\)a3\(2\) · 6.0\(2\)u3\(2\) · 6.0\(2\)u3\(3\) · 6.0\(2\)a3\(4\) · 6.0\(2\)u3\(4\) · 6.0\(2\)u3\(5\) · 6.0\(2\)u3\(6\) · 6.0\(2\)u3\(7\) · 6.0\(2\)u3\(8\) · 6.0\(2\)u3\(9\) · 6.0\(2\)a4\(1\) · 6.0\(2\)u4\(1\) · 6.0\(2\)a4\(2\) · 6.0\(2\)u4\(2\) · 6.0\(2\)a4\(3\) · 6.0\(2\)u4\(3\) · 6.0\(2\)a4\(4\) · 6.0\(2\)u4\(4\) · 6.0\(2\)a4\(5\) · 6.0\(2\)a4\(6\) · 6.0\(2\)u5\(1\) · 6.0\(2\)u5\(2\) · 6.0\(2\)u5\(3\) · 6.0\(2\)u5\(4\) · 6.0\(2\)a6\(1\) · 6.0\(2\)a6\(1a\) · 6.0\(2\)u6\(1\) · 6.0\(2\)u6\(1a\) · 6.0\(2\)a6\(2\) · 6.0\(2\)a6\(2a\) · 6.0\(2\)u6\(2\) · 6.0\(2\)u6\(2a\) · 6.0\(2\)a6\(3\) · 6.0\(2\)a6\(3a\) · 6.0\(2\)u6\(3\) · 6.0\(2\)u6\(3a\) · 6.0\(2\)a6\(4\) · 6.0\(2\)a6\(4a\) · 6.0\(2\)u6\(4\) · 6.0\(2\)u6\(4a\) · 6.0\(2\)a6\(5\) · 6.0\(2\)a6\(5a\) · 6.0\(2\)a6\(5b\) · 6.0\(2\)u6\(5\) · 6.0\(2\)u6\(5a\) · 6.0\(2\)u6\(5b\) · 6.0\(2\)u6\(5c\) · 6.0\(2\)a6\(6\) · 6.0\(2\)u6\(6\) · 6.0\(2\)a6\(7\) · 6.0\(2\)u6\(7\) · 6.0\(2\)a6\(8\) · 6.0\(2\)u6\(8\) · 6.0\(2\)u6\(9\) · 6.0\(2\)u6\(10\) · 6.0\(2\)u6\(10a\) · 6.0\(2\)a7\(1\) · 6.0\(2\)a7\(1a\) · 6.0\(2\)a7\(2\) · 6.0\(2\)a7\(2a\) · 6.0\(2\)a8\(1\) · 6.0\(2\)a8\(2\) · 6.0\(2\)a8\(3\) · 6.0\(2\)a8\(4\) · 6.0\(2\)a8\(4a\) · 6.0\(2\)a8\(5\) · 6.0\(2\)a8\(6\) · 6.0\(2\)a8\(7\) · 6.0\(2\)a8\(7a\) · 6.0\(2\)a8\(7b\) · 6.0\(2\)a8\(8\) · 6.0\(2\)a8\(9\) · 6.0\(2\)a8\(10\) · 6.0\(2\)a8\(10a\) · 6.0\(2\)a8\(11\) · 6.0\(2\)a8\(11a\) · 6.0\(2\)a8\(11b\) · 7.0\(0\)n1\(1\) · 7.0\(1\)n1\(1\) · 7.0\(2\)n1\(1\) · 7.0\(3\)n1\(1\) · 7.0\(3\)f1\(1\) · 7.0\(3\)i2\(1\) · 7.0\(3\)i2\(1a\) · 7.0\(3\)f2\(1\) · 7.0\(3\)i2\(2\) · 7.0\(3\)i2\(2a\) · 7.0\(3\)i2\(2b\) · 7.0\(3\)i2\(2c\) · 7.0\(3\)i2\(2d\) · 7.0\(3\)i2\(2e\) · 7.0\(3\)i2\(2r\) · 7.0\(3\)i2\(2s\) · 7.0\(3\)i2\(2v\) · 7.0\(3\)i2\(2w\) · 7.0\(3\)i2\(2x\) · 7.0\(3\)i2\(2y\) · 7.0\(3\)f2\(2\) · 7.0\(3\)i2\(3\) · 7.0\(3\)i2\(4\) · 7.0\(3\)i2\(5\) · 7.0\(3\)f3\(1\) · 7.0\(3\)i3\(1\) · 7.0\(3\)im3\(1\) · 7.0\(3\)f3\(2\) · 7.0\(3\)im3\(2\) · 7.0\(3\)im3\(2a\) · 7.0\(3\)im3\(2b\) · 7.0\(3\)f3\(3\) · 7.0\(3\)f3\(3a\) · 7.0\(3\)f3\(3c\) · 7.0\(3\)im3\(3\) · 7.0\(3\)f3\(4\) · 7.0\(3\)f3\(5\) · 7.0\(3\)i4\(1\) · 7.0\(3\)i4\(1t\) · 7.0\(3\)i4\(2\) · 7.0\(3\)i4\(3\) · 7.0\(3\)i4\(4\) · 7.0\(3\)ic4\(4\) · 7.0\(3\)i4\(5\) · 7.0\(3\)i4\(6\) · 7.0\(3\)i4\(6t\) · 7.0\(3\)i4\(7\) · 7.0\(3\)i4\(8\) · 7.0\(3\)i4\(8a\) · 7.0\(3\)i4\(8b\) · 7.0\(3\)i4\(8z\) · 7.0\(3\)i4\(9\) · 7.0\(3\)i5\(1\) · 7.0\(3\)i5\(2\) · 7.0\(3\)i5\(3\) · 7.0\(3\)i5\(3a\) · 7.0\(3\)i5\(3b\) · 7.0\(3\)i6\(1\) · 7.0\(3\)i6\(2\) · 7.0\(3\)i7\(1\) · 7.0\(3\)ia7\(1\) · 7.0\(3\)i7\(2\) · 7.0\(3\)im7\(2\) · 7.0\(3\)ia7\(2\) · 7.0\(3\)i7\(3\) · 7.0\(3\)i7\(3z\) · 7.0\(3\)i7\(4\) · 7.0\(3\)i7\(5\) · 7.0\(3\)i7\(5a\) · 7.0\(3\)i7\(6\) · 7.0\(3\)i7\(6z\) · 7.0\(3\)i7\(7\) · 7.0\(3\)i7\(8\) · 7.0\(4\)n1\(1\) · 7.0\(4\)n1\(1a\) · 7.0\(5\)n1\(1\) · 7.0\(5\)n1\(1a\) · 7.0\(6\)n1\(1\) · 7.0\(6\)n1\(2s\) · 7.0\(6\)n1\(3s\) · 7.0\(6\)n1\(4s\) · 7.0\(7\)n1\(1\) · 7.0\(7\)n1\(1a\) · 7.0\(7\)n1\(1b\) · 7.0\(8\)n1\(1\) · 7.0\(8\)n1\(1a\) · 7.1\(0\)n1\(1\) · 7.1\(0\)n1\(1a\) · 7.1\(0\)n1\(1b\) · 7.1\(1\)n1\(1\) · 7.1\(1\)n1\(1a\) · 7.1\(2\)n1\(1\) · 7.1\(2\)n1\(1a\) · 7.1\(3\)n1\(1\) · 7.1\(3\)n1\(2\) · 7.1\(3\)n1\(2a\) · 7.1\(3\)n1\(3\) · 7.1\(3\)n1\(4\) · 7.1\(3\)n1\(5\) · 7.1\(4\)n1\(1\) · 7.1\(4\)n1\(1a\) · 7.1\(4\)n1\(1c\) · 7.1\(4\)n1\(1d\) · 7.1\(5\)n1\(1\) · 7.1\(5\)n1\(1b\) · 7.2\(0\)n1\(1\) · 7.2\(0\)d1\(1\) · 7.2\(1\)n1\(1\) · 7.2\(1\)d1\(1\) · 7.2\(2\)d1\(1\) · 7.2\(2\)d1\(2\) · 7.2\(2\)d1\(3\) · 7.2\(2\)d1\(4\) · 7.3\(0\)dx\(1\) · 7.3\(0\)n1\(1\) · 7.3\(0\)n1\(1a\) · 7.3\(0\)n1\(1b\) · 7.3\(0\)d1\(1\) · 7.3\(1\)n1\(1\) · 7.3\(1\)d1\(1\) · 7.3\(2\)n1\(1\) · 7.3\(2\)n1\(1b\) · 7.3\(2\)n1\(1c\) · 7.3\(2\)d1\(1\) · 7.3\(2\)d1\(1d\) · 7.3\(2\)d1\(2\) · 7.3\(2\)d1\(3\) · 7.3\(2\)d1\(3a\) · 7.3\(3\)n1\(1\) · 7.3\(3\)d1\(1\) · 7.3\(4\)n1\(1\) · 7.3\(4\)n1\(1a\) · 7.3\(4\)d1\(1\) · 7.3\(5\)n1\(1\) · 7.3\(5\)d1\(1\) · 7.3\(6\)n1\(1\) · 7.3\(6\)n1\(1a\) · 7.3\(6\)d1\(1\) · 7.3\(7\)n1\(1\) · 7.3\(7\)n1\(1a\) · 7.3\(7\)n1\(1b\) · 8.0\(1\) · 8.1\(1\) · 8.1\(2\) · 8.1\(2a\) · 8.2\(1\) · 8.2\(2\) · 8.2\(3\) · 8.2\(4\) · 8.2\(5\) · 8.3\(1\) · 8.3\(2\) · 8.4\(1\) · 8.4\(2\) |
| nvd | cisco | unified computing system | generic | ≥ 4.0 and < 4.0.4 · ≥ 4.1 and < 4.1.1 |
References
| URL | Tags |
|---|---|
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-ipv6-netstack-edXPGV7K | Vendor Advisory |
Timeline
Timeline
| Published | 2021-02-24 | By the CVE Program. |
|---|---|---|
| NVD record modified | 2026-06-17 | NVD's own last-modified date for this record. |