CVE-2021-1498: Cisco HyperFlex HX web management interface command injection

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 16 September 2026. Confidence: high.

critical priorityCVSS 9.8 with no authentication or interaction required, confirmed KEV listing, near-maximum EPSS, and public exploit code make this an urgent, actively targeted flaw.

What it is

The web-based management interface of Cisco HyperFlex HX contains command injection flaws (CWE-78/CWE-77) that let an unauthenticated, remote attacker run commands on the affected device. With a CVSS 3.1 score of 9.8 and no privileges or user interaction required, this is a full-compromise class issue for any exposed management interface.

Impact

An attacker gains arbitrary command execution on the HyperFlex HX appliance, which can lead to full control of the device and any data or credentials it holds.

Attack surface

Reached over the network through the web-based management interface (AV:N, PR:N, UI:N). No authentication or user interaction is needed, so any internet- or network-exposed management endpoint is directly at risk.

Exploitation

CISA added it to KEV on 2021-11-03 with a 2021-11-17 remediation due date, and EPSS is 0.99999 (99.991st percentile); public exploit code is referenced via Packet Storm. No ransomware campaign use is documented in this record.

What to do

• Apply the Cisco HyperFlex HX updates referenced in the vendor advisory cisco-sa-hyperflex-rce-TjjNrkpR as the first action.
• Remove the HyperFlex HX management interface from direct internet exposure and restrict it to a trusted management network or VPN.
• Enforce network access controls and firewall rules limiting who can reach the management interface.
• Monitor for and investigate any signs of compromise on HyperFlex HX appliances, since exploitation is known and widespread.
• Track the CISA KEV due date to confirm remediation is completed.

Detection

• Review web server and appliance logs for unusual requests to the HyperFlex HX management interface, especially patterns consistent with command injection.
• Alert on unexpected or suspicious child processes spawned by the web management service on HyperFlex HX hosts.
• Monitor outbound connections from HyperFlex HX appliances to unknown external hosts for signs of post-exploitation activity.
• Correlate network access logs to identify any external or untrusted sources reaching the management interface.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.