CVE-2019-1965 : What You Need to Know

A weakness has been discovered in the session management of the Virtual Shell (VSH) for Cisco NX-OS Software, potentially leading to a denial of service (DoS) situation due to memory depletion.

Understanding CVE-2019-1965

What is CVE-2019-1965?

The vulnerability in Cisco NX-OS Software allows an authorized remote attacker to prevent the deletion of a VSH process upon termination, leading to memory depletion and system crashes.

The Impact of CVE-2019-1965

The vulnerability can result in a system-wide denial of service (DoS) situation due to memory depletion, potentially causing unexpected system behaviors and crashes.

Technical Details of CVE-2019-1965

Vulnerability Description

The vulnerability arises from the improper deletion of the VSH process when a remote management connection to the device is disconnected.

Affected Systems and Versions

Product: Cisco NX-OS Software
Vendor: Cisco
Versions Affected: Less than 8.4(1)

Exploitation Mechanism

An attacker with valid user credentials can repeatedly establish and terminate remote management connections to prevent VSH process deletion.

Mitigation and Prevention

Immediate Steps to Take

Apply vendor-provided patches or updates to address the vulnerability.
Monitor system memory usage for any unusual spikes.

Long-Term Security Practices

Implement strong user credential management practices.
Regularly review and update system configurations to enhance security.

Patching and Updates

Stay informed about security advisories from Cisco and apply patches promptly to mitigate risks.