CVE-2018-0136 Explained : Impact and Mitigation

A vulnerability in the IPv6 subsystem of Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series could allow an unauthenticated, remote attacker to trigger a reload of one or more Trident-based line cards, resulting in a denial of service (DoS) condition.

Understanding CVE-2018-0136

This CVE entry describes a specific vulnerability in Cisco Aggregation Services Router (ASR) 9000 Series devices.

What is CVE-2018-0136?

The vulnerability in the IPv6 subsystem of Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series allows a remote attacker to cause Trident-based line cards to reload, leading to a DoS condition.

The Impact of CVE-2018-0136

An unauthenticated attacker can exploit the vulnerability to trigger a reload of Trident-based line cards, causing a DoS situation.

Technical Details of CVE-2018-0136

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The flaw is due to mishandling of IPv6 packets with a fragment header extension.

Affected Systems and Versions

Cisco Aggregation Services Router 9000 Series running Cisco IOS XR Software Release 5.3.4 with Trident-based line cards and IPv6 configuration.

Exploitation Mechanism

Attacker sends crafted IPv6 packets to trigger the vulnerability on Trident-based line cards.

Mitigation and Prevention

Steps to address and prevent exploitation of CVE-2018-0136.

Immediate Steps to Take

Apply the software maintenance upgrade (SMU) or install service pack 7 for Cisco IOS XR Software Release 5.3.4.

Long-Term Security Practices

Regularly update and patch Cisco devices to prevent known vulnerabilities.

Patching and Updates

Ensure all Cisco Aggregation Services Router 9000 Series devices are updated with the necessary patches and upgrades.