CVE-2021-1573 : Security Advisory and Response

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software allows an unauthenticated, remote attacker to trigger a denial of service (DoS) condition by sending a malicious HTTPS request.

Understanding CVE-2021-1573

This CVE affects Cisco's Adaptive Security Appliance Software and Firepower Threat Defense Software, potentially leading to a DoS attack.

What is CVE-2021-1573?

The vulnerability in the web services interface of Cisco ASA and FTD Software enables an attacker to exploit improper input validation in HTTPS requests, causing a DoS condition.

The Impact of CVE-2021-1573

The vulnerability poses a high availability impact with a CVSS base score of 8.6, allowing remote attackers to reload affected devices.

Technical Details of CVE-2021-1573

This section outlines the specific technical details of the vulnerability.

Vulnerability Description

The flaw arises from inadequate input validation in parsing HTTPS requests, enabling attackers to disrupt device operation.

Affected Systems and Versions

Cisco Adaptive Security Appliance Software versions less than 6.4.0.13 and Firepower Threat Defense Software versions less than 6.6.5 are affected.

Exploitation Mechanism

Attackers can exploit this vulnerability by sending a malicious HTTPS request, inducing the affected device to reload and trigger a DoS situation.

Mitigation and Prevention

To secure systems from CVE-2021-1573, the following measures can be implemented.

Immediate Steps to Take

Users are advised to apply vendor-supplied patches promptly. Network level protections can also help mitigate the risk.

Long-Term Security Practices

Regularly monitor device logs for suspicious activities and keep systems updated with the latest security patches.

Patching and Updates

Stay informed about security advisories and apply relevant patches from the vendor to safeguard systems.