CVE-2019-16026 Explained : Impact and Mitigation

A security flaw has been discovered in the Cisco Mobility Management Entity (MME) where the implementation of the Stream Control Transmission Protocol (SCTP) is vulnerable. This flaw could potentially allow a remote attacker without authentication to initiate a denial of service (DoS) attack on an eNodeB that is connected to the affected device. The vulnerability stems from inadequate validation of SCTP traffic inputs. To exploit this vulnerability, an attacker would need to occupy a man-in-the-middle position between the eNodeB and the MME, and then transmit a specially crafted SCTP message to the MME. If successful, this attack would cause the MME to cease sending SCTP messages to the eNodeB, resulting in a DoS situation.

Understanding CVE-2019-16026

This section provides insights into the impact and technical details of the CVE.

What is CVE-2019-16026?

CVE-2019-16026 is a vulnerability in the implementation of the SCTP on Cisco Mobility Management Entity (MME) that could lead to a DoS condition on an eNodeB connected to the affected device.

The Impact of CVE-2019-16026

The vulnerability has the following impact:

CVSS Base Score: 6.8 (Medium)
Attack Vector: Network
Attack Complexity: High
Availability Impact: High
Scope: Changed

Technical Details of CVE-2019-16026

This section delves into the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The vulnerability arises from insufficient input validation of SCTP traffic on the Cisco MME.

Affected Systems and Versions

Affected Product: Cisco ASR 5000 Series Software
Vendor: Cisco
Affected Version: Unspecified

Exploitation Mechanism

To exploit this vulnerability, an attacker must:

Be in a man-in-the-middle position between the eNodeB and the MME
Send a crafted SCTP message to the MME
Cause the MME to stop sending SCTP messages to the eNodeB, leading to a DoS condition.

Mitigation and Prevention

This section outlines steps to mitigate and prevent the CVE.

Immediate Steps to Take

Implement network segmentation to limit exposure
Apply the latest security patches from Cisco
Monitor network traffic for any suspicious activity

Long-Term Security Practices

Conduct regular security assessments and audits
Educate staff on cybersecurity best practices
Keep systems up to date with the latest security measures

Patching and Updates

Regularly check for security advisories from Cisco
Apply patches promptly to address known vulnerabilities