CVE-2022-20960 : What You Need to Know

This article provides detailed information about CVE-2022-20960, a vulnerability in Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) that could lead to a denial of service (DoS) attack.

Understanding CVE-2022-20960

CVE-2022-20960 is a vulnerability in Cisco Email Security Appliance (ESA) that allows an unauthenticated remote attacker to cause a DoS condition on an affected device by exploiting improper handling of certain TLS connections.

What is CVE-2022-20960?

The vulnerability in Cisco AsyncOS Software for Cisco Email Security Appliance allows an attacker to establish a large number of concurrent TLS connections to an affected device, causing it to drop new TLS email messages from associated email servers.

The Impact of CVE-2022-20960

The exploitation of this vulnerability does not trigger the affected device to unexpectedly reload. However, the device will recover autonomously within a few hours once the attack is halted or mitigated.

Technical Details of CVE-2022-20960

Vulnerability Description

The vulnerability is caused by improper handling of TLS connections in the affected device, leading to a DoS condition when exploited by an attacker.

Affected Systems and Versions

Multiple versions of Cisco Email Security Appliance (ESA) are affected, including versions 10.0.1-087 to 14.2.0-620.

Exploitation Mechanism

Attackers can exploit the vulnerability by establishing numerous concurrent TLS connections, resulting in dropped email messages.

Mitigation and Prevention

Immediate Steps to Take

Cisco recommends applying the necessary updates and configurations to mitigate the risk of exploitation.

Long-Term Security Practices

Implementing network security best practices and monitoring for abnormal network activity can help prevent such vulnerabilities.

Patching and Updates

Ensure that affected systems are updated with the latest patches provided by Cisco to address the CVE-2022-20960 vulnerability.