Symptom
A vulnerability in the FTP inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass FTP inspection.
The vulnerability is due to ineffective flow tracking of FTP traffic. An attacker could exploit this vulnerability by sending crafted FTP traffic through an affected device. A successful exploit could allow the attacker to bypass FTP inspection and successfully complete FTP connections.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ftpbypass-HY3UTxYu
Conditions
Please refer to the Security Advisory.
Workaround
Please refer to the Security Advisory.
Further Problem Description
Please refer to the Security Advisory.
PSIRT Evaluation
The Cisco PSIRT has assigned this bug the following CVSS version 3 score. The Base CVSS score as of the time of evaluation is 5.8:
https://tools.cisco.com/security/center/cvssCalculator.x?vector=CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
CVE ID CVE-2020-3564 has been assigned to document this issue.
Information about Fixed, Vulnerable, and Nonvulnerable releases--as well as information about fixed release availability--is not maintained by Cisco PSIRT. Please refer to the appropriate fields in this bug. If you require additional help to obtain this information, please open a support case with your support organization.
Additional information on Cisco's security vulnerability policy can be found at the following URL:
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
