CVE-2020-3577: Cisco Firepower Threat Defense Software Inline Pair/Passive Mode Denial of Service Vulnerability
A vulnerability in the ingress packet processing path of Cisco Firepower Threat Defense (FTD) Software for interfaces that are configured either as Inline Pair or in Passive mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient validation when Ethernet frames are processed. An attacker could exploit this vulnerability by sending malicious Ethernet frames through an affected device. A successful exploit could allow the attacker do either of the following: Fill the /ngfw partition on the device: A full /ngfw partition could result in administrators being unable to log in to the device (including logging in through the console port) or the device being unable to boot up correctly. Note: Manual intervention is required to recover from this situation. Customers are advised to contact the Cisco Technical Assistance Center (TAC) to help recover a device in this condition. Cause a process crash: The process crash would cause the device to reload. No manual intervention is necessary to recover the device after the reload.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Contact Cisco TAC for help recovering the device if it becomes stuck due to a full /ngfw partition (administrators unable to log in or device unable to boot correctly) after exploitation.
- Operational
If the device enters the denial-of-service condition and reloads, follow the note that no manual intervention is necessary to recover after the reload (or note that manual intervention is required to recover from the /ngfw full partition condition as described).
Event History
Frequently Asked Questions
What is the severity of CVE-2020-3577?
The severity of CVE-2020-3577 is high.
How does CVE-2020-3577 affect Cisco Firepower Threat Defense software?
CVE-2020-3577 affects Cisco Firepower Threat Defense software versions between 6.3.0.6 and 6.6.1.
What is the vulnerability in CVE-2020-3577?
CVE-2020-3577 is a vulnerability in the ingress packet processing path of Cisco Firepower Threat Defense software.
How can an attacker exploit CVE-2020-3577?
An unauthenticated, adjacent attacker can exploit CVE-2020-3577 by causing a denial of service condition on affected interfaces.
Is there a fix available for CVE-2020-3577?
Yes, Cisco has released software updates to address the vulnerability. Please refer to the vendor advisory for more information.