CVE-2024-20399 — NX-OS
MEDIUMCVE-2024-20399 is a medium-severity (CVSS 6) OS Command Injection vulnerability in cisco nx-os. It is in CISA's Known Exploited Vulnerabilities catalog (added 2024-07-02) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
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…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2024-07-02. Federal agencies were required to remediate by 2024-07-23.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2024-20399.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2024-20399 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
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
Affected Products
nx-osciscoResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every cisco nx-os deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2024-20399 yet — track the cisco nx-os advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2024-20399 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.