Cisco NX-OS Software Remote Management Memory Leak Denial of Service Vulnerability

published 2019-08-28 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-10522

cvss: 7.7; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits: 0; none known

A vulnerability in the Virtual Shell (VSH) session management for Cisco NX-OS Software could allow an authenticated, remote attacker to cause a VSH process to fail to delete upon termination. This can lead to a build-up of VSH processes that overtime can deplete system memory. When there is no system memory available, this can cause unexpected system behaviors and crashes. The vulnerability is due to the VSH process not being properly deleted when a remote management connection to the device is disconnected. An attacker could exploit this vulnerability by repeatedly performing a remote management connection to the device and terminating the connection in an unexpected manner. A successful exploit could allow the attacker to cause the VSH processes to fail to delete, which can lead to a system-wide denial of service (DoS) condition. The attacker must have valid user credentials to log in to the device using the remote management connection.

Patch / fix

fixed in 1

Cisco Cisco NX-OS Software 8.4(1)

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 23 mo ago (2024-11-21)

Exploit prediction

1.53% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	7.7	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
NVD	3.1	7.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
NVD	2.0	4.0	AV:N/AC:L/Au:S/C:N/I:N/A:P

Affected products

Cisco Cisco NX-OS Software

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-772 Missing Release of Resource after Effective Lifetime

References

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-20190828-nxos-memleak-dos
vendor-advisory

Sources

CVE List CVE-2019-1965
NVD CVE-2019-1965

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Summary