CVE-2019-1951 Explained : Impact and Mitigation

Cisco SD-WAN Solution Packet Filtering Bypass Vulnerability

Understanding CVE-2019-1951

This CVE involves a vulnerability in the packet filtering capabilities of the Cisco SD-WAN Solution, potentially allowing remote attackers to bypass traffic filters.

What is CVE-2019-1951?

The vulnerability in the Cisco SD-WAN Solution allows unauthorized remote attackers to circumvent L3 and L4 traffic filters by exploiting improper traffic filtering conditions on affected devices.

The Impact of CVE-2019-1951

If successfully exploited, attackers can introduce arbitrary packets into the network, evading L3 and L4 traffic filters.

Technical Details of CVE-2019-1951

The following are the technical details of this CVE:

Vulnerability Description

The issue arises from improper conditions for filtering traffic on impacted devices, enabling attackers to bypass traffic filters.

Affected Systems and Versions

Product: Cisco SD-WAN Solution
Vendor: Cisco
Versions Affected: Less than 19.1.0 (unspecified version type)

Exploitation Mechanism

Attackers can exploit this vulnerability by creating a malicious TCP packet with specific attributes and directing it towards a targeted device.

Mitigation and Prevention

To address CVE-2019-1951, consider the following steps:

Immediate Steps to Take

Apply vendor-provided patches or updates promptly.
Monitor network traffic for any signs of malicious activity.

Long-Term Security Practices

Regularly update and patch all software and firmware.
Implement network segmentation to limit the impact of potential breaches.

Patching and Updates

Ensure that the Cisco SD-WAN Solution is updated to a version equal to or greater than 19.1.0 to mitigate the vulnerability.