CVE-2021-40125 : What You Need to Know

This CVE article provides insights into a vulnerability affecting Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software.

Understanding CVE-2021-40125

This section delves into the details surrounding the IKEv2 Site-to-Site VPN Denial of Service Vulnerability.

What is CVE-2021-40125?

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) implementation of Cisco ASA Software and FTD Software allows a remote attacker to trigger a DoS condition by sending malformed IKEv2 messages.

The Impact of CVE-2021-40125

The vulnerability could be exploited by an authenticated attacker, potentially leading to a denial of service by causing a reload of the affected device.

Technical Details of CVE-2021-40125

This section provides technical insights into the vulnerability.

Vulnerability Description

The flaw arises from improper resource control in the IKEv2 implementation, enabling an attacker with valid credentials to cause a DoS condition.

Affected Systems and Versions

Product: Cisco Adaptive Security Appliance (ASA) Software
Vendor: Cisco
Version: n/a

Exploitation Mechanism

Attacker spoofs a trusted IKEv2 site-to-site VPN peer
Possesses valid IKEv2 credentials
Sends malformed, authenticated IKEv2 messages to trigger a device reload

Mitigation and Prevention

Learn about the steps to mitigate and prevent this vulnerability.

Immediate Steps to Take

Apply vendor-provided patches
Implement network segmentation
Monitor and restrict network traffic

Long-Term Security Practices

Regularly update and patch software
Conduct security training for personnel

Patching and Updates

Update to the latest version of Cisco ASA Software and FTD Software
Follow vendor recommendations for security best practices