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CVE-2024-20399 - Cisco NX-OS Software CLI Command Injection Vulnerability (Last Updated: 17-Sep-2024)
CVE-2024-20399 KEVPublic exploit Medium · 6.7 EPSS 4.3%
Cisco NX-OS Command Injection Vulnerability
Cisco · NX-OS
Summary
The flaw is a command injection vulnerability in the CLI of Cisco NX-OS Software, caused by insufficient validation of arguments passed to certain configuration CLI commands. An attacker who holds Administrator credentials on an affected device can use crafted input in those commands to run arbitrary commands as root on the underlying operating system; the attack requires local access to the CLI and no user interaction.
Official description · NVD
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
Priority scorePatchfirst’s 0 to 100 ranking. It adds points for CISA KEV listing, ransomware use, EPSS, threat reports, public exploit code and CVSS. Every CVE page shows the breakdown. Breakdown
73.7 / 100
- Exploited
- Yes, in CISA KEV
- Reports
- 3
- Tactics
- 5/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.How attackers get in
What they do
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited the day it was disclosed. Public exploit code (PoC-in-GitHub) appeared 24 months after disclosure.
- First dated threat reportsygnia.co21 mo before
- Added to CISA KEVEU database agrees+1 day
- Public exploit codePoC-in-GitHub+24 mo
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 2Initial AccessTA0001
MITRE CTID mapping of the KEV entry · how it is exploited
This vulnerability is exploited by an attacker who has access to administrator credentials. The adversary leverages these credentials to execute arbitrary commands using root privileges.
ExecutionTA0002
MITRE CTID mapping of the KEV entry · primary impact
Detection
0 rules for this CVE · 151 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2024-20399 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Valid AccountsT107856 general rules
- Win Susp Computer Name Containing Samtheadmincriticaltest
- Account Created And Deleted Within A Close Time Framehightest
- Activity From Anonymous IP Addresshightest
- Atypical Travelhightest
- Azure AD Threat Intelligencehightest
- Azure Subscription Permission Elevation Via AuditLogshightest
- External Remote SMB Logon from Public IPhightest
- Impossible Travelhightest
Command and Scripting InterpreterT105995 general rules
- HackTool - Sliver C2 Implant Activity Patterncriticaltest
- Lazarus Group Activitycriticaltest
- REvil Kaseya Incident Malware Patternscriticaltest
- Turla Group Lateral Movementcriticaltest
- Windows Defender AMSI Trigger Detectedhighstable
- Windows Defender Threat Detectedhighstable
- Abusable DLL Potential Sideloading From Suspicious Locationhightest
- Add Insecure Download Source To Wingethightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Named in 3 threat reports3 reportssygnia.co2Cisco TalosOct 2022 – Feb 2025
Reports are matched by finding the exact id CVE-2024-20399 in their text; nobody has reviewed the match. One passage is shown per report, at most 320 characters, linked to the original.
In-Depth Analysis: Velvet Ant's Prolonged Cyber Attack on a Large Organization
China-Nexus Threat Group ‘Velvet Ant’ Exploits Cisco Zero-Day (CVE-2024-20399) to Compromise Nexus Switch Devices – Advisory for Mitigation and Response…
Revealing Emperor Dragonfly: Night Sky and Cheerscrypt - A Single Ransomware Group
China-Nexus Threat Group ‘Velvet Ant’ Exploits Cisco Zero-Day (CVE-2024-20399) to Compromise Nexus Switch Devices – Advisory for Mitigation and Response…
Also mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 30, 202629 Oct 2026
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- 44 more on OTX