CVE-2018-0241 Explained : Impact and Mitigation

Cisco IOS XR Software's UDP broadcast forwarding feature has a security flaw that could lead to a denial of service (DoS) attack. Learn about the impact, affected systems, and mitigation steps.

Understanding CVE-2018-0241

A vulnerability in Cisco IOS XR Software could allow an unauthorized attacker to exploit the UDP broadcast forwarding function, potentially causing a DoS condition on the affected device.

What is CVE-2018-0241?

The vulnerability arises from the mishandling of UDP broadcast packets directed to an IPv4 helper address, enabling an attacker in close proximity to the device to trigger a DoS situation by flooding it with UDP broadcast packets.

The Impact of CVE-2018-0241

Unauthorized attackers can exploit the flaw to cause a denial of service (DoS) condition on the affected device.
The vulnerability could lead to a buffer leak on the device, requiring manual intervention to restore normal operation.

Technical Details of CVE-2018-0241

Cisco IOS XR Software vulnerability details and affected systems.

Vulnerability Description

Improper handling of UDP broadcast packets forwarded to an IPv4 helper address.
Exploitable by sending multiple UDP broadcast packets to the device.

Affected Systems and Versions

All Cisco IOS XR platforms running versions 6.3.1, 6.2.3, or earlier with at least one IPv4 helper address configured.

Exploitation Mechanism

Attackers exploit the vulnerability by flooding the device with UDP broadcast packets, causing a buffer leak and a subsequent DoS condition.

Mitigation and Prevention

Steps to mitigate the CVE-2018-0241 vulnerability.

Immediate Steps to Take

Apply the necessary patches provided by Cisco to address the vulnerability.
Monitor network traffic for any signs of unusual UDP broadcast packet activity.

Long-Term Security Practices

Regularly update and patch Cisco IOS XR Software to prevent known vulnerabilities.
Implement network segmentation and access controls to limit exposure to potential attacks.

Patching and Updates

Cisco has released patches to address the vulnerability in affected versions of Cisco IOS XR Software.