CVE-2021-34720 : What You Need to Know

A vulnerability in the IP Service Level Agreements (IP SLA) responder and Two-Way Active Measurement Protocol (TWAMP) features of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition by crashing the IP SLA process or exhausting device packet memory.

Understanding CVE-2021-34720

This CVE describes a vulnerability in Cisco IOS XR Software that could be exploited by a remote attacker to trigger a DoS attack.

What is CVE-2021-34720?

This CVE pertains to a vulnerability in the IP SLA responder and TWAMP features of Cisco IOS XR Software that may lead to a DoS condition when mismanaged socket creation failures occur during the IP SLA and TWAMP processes.

The Impact of CVE-2021-34720

The vulnerability could result in the exhaustion of packet memory on affected devices, leading to the crashing of the IP SLA process or impacting other critical processes like routing protocols.

Technical Details of CVE-2021-34720

The following technical details shed light on the specifics of CVE-2021-34720.

Vulnerability Description

The vulnerability stems from mishandling socket creation failures in the IP SLA and TWAMP processes, enabling attackers to send malicious packets that exhaust packet memory.

Affected Systems and Versions

The affected product is Cisco IOS XR Software, with all versions being impacted by this vulnerability.

Exploitation Mechanism

Exploiting this vulnerability involves sending specific IP SLA or TWAMP packets to the target device, thereby causing a DoS condition.

Mitigation and Prevention

To address CVE-2021-34720, consider the following mitigation strategies.

Immediate Steps to Take

Immediately apply patches and updates from the vendor to remediate the vulnerability and prevent exploitation.

Long-Term Security Practices

Implement network segmentation, access controls, and monitoring to enhance overall security posture and detect anomalous network activity.

Patching and Updates

Regularly monitor vendor security advisories and promptly apply patches and updates to mitigate vulnerabilities and enhance system security.