CVE-2021-1592: Cisco Unified Computing System

Medium severity, CVSS 4.3. EPSS: 1% chance of exploitation in the next 30 days.

A vulnerability in the way Cisco UCS Manager software handles SSH sessions could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper resource management for established SSH sessions. An attacker could exploit this vulnerability by opening a significant number of SSH sessions on an affected device. A successful exploit could allow the attacker to cause a crash and restart of internal Cisco UCS Manager software processes and a temporary loss of access to the Cisco UCS Manager CLI and web UI. Note: The attacker must have valid user credentials to authenticate to the affected device.

Affected products

• Cisco Unified Computing System: from 4.0, before 4.0\(4m\) (fixed in 4.0\(4m\)); from 4.1, before 4.1\(3e\) (fixed in 4.1\(3e\))

Published 2021-08-25. Last modified 2026-06-17.