CVE-2021-1566 Explained : Impact and Mitigation
Learn about CVE-2021-1566, a high-severity certificate validation vulnerability in Cisco Email Security Appliance and Cisco Web Security Appliance that allows remote attackers to intercept and manipulate traffic.
A vulnerability in the Cisco Advanced Malware Protection (AMP) for Endpoints integration of Cisco AsyncOS for Cisco Email Security Appliance (ESA) and Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to intercept traffic between an affected device and the AMP servers.
Understanding CVE-2021-1566
This CVE refers to a certificate validation vulnerability in Cisco Email Security Appliance (ESA) and Cisco Web Security Appliance (WSA) that could be exploited by an attacker to intercept and manipulate traffic.
What is CVE-2021-1566?
The vulnerability allows a remote attacker to perform man-in-the-middle attacks by exploiting improper certificate validation during TLS connections.
The Impact of CVE-2021-1566
An attacker could intercept traffic, spoof trusted hosts, and extract sensitive information or manipulate API requests, posing a high confidentiality and integrity risk.
Technical Details of CVE-2021-1566
The vulnerability is rated with a CVSS base score of 7.4, indicating a high severity level and the potential for significant damage if exploited.
Vulnerability Description
The flaw lies in the improper certificate validation process when establishing TLS connections, enabling attackers to send crafted packets to compromise devices.
Affected Systems and Versions
The vulnerability affects Cisco Web Security Appliance (WSA) with all versions.
Exploitation Mechanism
A man-in-the-middle attacker can exploit the vulnerability by sending a specially crafted TLS packet to affected devices, allowing them to intercept and manipulate traffic.
Mitigation and Prevention
To mitigate the risk associated with CVE-2021-1566, immediate and long-term security practices need to be implemented.
Immediate Steps to Take
Organizations should apply security patches provided by Cisco and closely monitor network traffic for any signs of suspicious activity.
Long-Term Security Practices
Implement robust TLS encryption practices, regularly update security configurations, and conduct security awareness training for employees.
Patching and Updates
Cisco has released patches to address the vulnerability. Users are advised to update their Cisco Web Security Appliance (WSA) to the latest version available.