CVE-2021-34737 : Vulnerability Insights and Analysis

A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition.

Understanding CVE-2021-34737

This CVE identified in Cisco IOS XR Software points to a denial of service vulnerability in the DHCPv4 server feature, potentially leading to service disruption.

What is CVE-2021-34737?

The vulnerability allows a remote attacker to crash the dhcpd process by sending a malformed DHCPv4 message to the device, causing temporary unavailability of DHCPv4 server services.

The Impact of CVE-2021-34737

Exploitation of this vulnerability could disrupt network services for up to two minutes, affecting client network access during this period.

Technical Details of CVE-2021-34737

The vulnerability is categorized with a CVSS v3.1 Base Score of 5.8 and a Medium severity rating.

Vulnerability Description

Certain DHCPv4 messages are improperly validated, leading to a NULL pointer dereference and crash of the dhcpd process.

Affected Systems and Versions

Cisco IOS XR Software versions are affected by this vulnerability.

Exploitation Mechanism

An attacker can exploit the flaw by sending a malformed DHCPv4 message to a vulnerable device.

Mitigation and Prevention

Steps can be taken to mitigate the impact of CVE-2021-34737 and prevent future occurrences.

Immediate Steps to Take

Cisco has not detected any public exploitation or announcements related to this vulnerability. However, organizations should deploy patches promptly.

Long-Term Security Practices

Maintain awareness of security updates and best practices to enhance network security.

Patching and Updates

Refer to the provided Cisco advisory for detailed information on patches and updates.