# CVE-2024-20399 — Cisco NX-OS Software **CISA KEV** > As of 2025-10-21, CVE-2024-20399 is a MEDIUM-severity vulnerability in Cisco NX-OS Software, CVSS v3.1 6, EPSS 4.3% (90.9th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-07-02), with a US federal remediation deadline of 2024-07-23. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2024-20399, most recently “Velvet Ant (Operation Highland): Backdoored Linux PAM and OpenSSH for ~Decade-Long Espionage Persistence”. **Last updated:** 2025-10-21 ## What is CVE-2024-20399? 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 The record classifies CVE-2024-20399 under weakness class [CWE-78](https://intel.threadlinqs.com/cwe/CWE-78). Its CVSS v3 base vector states that the flaw requires local access to the host, needs high-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 846 days ago. ## Severity and exploitation probability - **CVSS v3.1 base score:** 6 — MEDIUM (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N`) - **EPSS (FIRST):** 4.3% probability of exploitation in the next 30 days, higher than 90.9% of all scored CVEs - **CISA KEV:** Listed since 2024-07-02, federal remediation deadline 2024-07-23 - **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9 - **Published:** 2024-07-01, last modified 2025-10-21 ## Is CVE-2024-20399 being exploited? CISA added CVE-2024-20399 to the Known Exploited Vulnerabilities catalog on 2024-07-02, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2024-07-23 under BOD 22-01. Weaponised exploit code for CVE-2024-20399 is publicly available. 2 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 46 in the Threadlinqs vulnerability feed. - [HORKimhab/CVE-2024-20399](https://github.com/HORKimhab/CVE-2024-20399) (github) - [trickest/cve](https://github.com/trickest/cve/blob/main/2024/CVE-2024-20399.md) (trickest) ## Affected products and versions - [Cisco](https://intel.threadlinqs.com/vendors/cisco): NX-OS Software ## How to fix CVE-2024-20399 Vendor advisory: [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-cmd-injection-xD9OhyOP](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-cmd-injection-xD9OhyOP). Because CVE-2024-20399 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2024-07-23. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory. ## Threat activity tracking CVE-2024-20399 1 tracked threat in the Threadlinqs corpus references CVE-2024-20399, either in the campaign’s CVE list or as an indicator on the campaign record. - [Velvet Ant (Operation Highland): Backdoored Linux PAM and OpenSSH for ~Decade-Long Espionage Persistence](https://intel.threadlinqs.com/threat/TL-2026-0807) — CRITICAL · 2026-06-15 ## Sources Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-11. This product uses the NVD API but is not endorsed or certified by the NVD. **Other references** - [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-cmd-injection-xD9OhyOP) Canonical: https://intel.threadlinqs.com/cve/CVE-2024-20399 Full detection coverage and IOCs for threats exploiting CVE-2024-20399 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp