CVE-2024-20399 — Cisco NX-OS Software CLI Command Injection Vulnerability

Summary

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated user in possession of Administrator credentials to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of arguments that are passed to specific configuration CLI commands. An attacker could exploit this vulnerability by including crafted input as the argument of an affected configuration CLI command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privileges of root. Note: To successfully exploit this vulnerability on a Cisco NX-OS device, an attacker must have Administrator credentials. The following Cisco devices already allow administrative users to access the underlying operating system through the bash-shell feature, so, for these devices, this vulnerability does not grant any additional privileges: Nexus 3000 Series Switches Nexus 7000 Series Switches that are running Cisco NX-OS Software releases 8.1(1) and later Nexus 9000 Series Switches in standalone NX-OS mode

Weakness: CWE-78

Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.

Affected and fixed versions

Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.

Remediation

Known exploitation

4% probability of exploitation in the next 30 days (percentile 91%).

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CERT-FR

No CERT-FR advisory or alert of the last two years references this CVE, for the vendors Patcharo covers.

Timeline

1. 1 Jul 2024Published by the source
2. 2 Jul 2024Added to CISA KEV
3. 23 Jul 2024CISA remediation due date
4. 17 Jun 2026Source record last modified
5. 29 Sept 2026EPSS score computed
6. 1 Oct 2026Last verified by Patcharo

Official sources

• Cisco (CVE record)retrieved 1 Oct 2026 at 13:37 UTC
• CISA Known Exploited Vulnerabilitiesretrieved 1 Oct 2026 at 13:37 UTC
• NVDretrieved 27 Sept 2026 at 23:44 UTC
• FIRST EPSSretrieved 30 Sept 2026 at 00:17 UTC
• Cisco Security Advisory cisco-sa-nxos-cmd-injection-xD9OhyOPretrieved 1 Oct 2026 at 13:37 UTC

Cisco · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · Cisco Security Advisory cisco-sa-nxos-cmd-injection-xD9OhyOP