FortiOS / FortiProxy / FortiSwitchManager - Authentication bypass on administrative interface

FortiOS / FortiProxy / FortiSwitchManager - Authentication bypass on administrative interface

Summary

An authentication bypass using an alternate path or channel vulnerability [CWE-288] in FortiOS, FortiProxy and FortiSwitchManager may allow an unauthenticated attacker to perform operations on the administrative interface via specially crafted HTTP or HTTPS requests.

 

Exploitation Status:

Fortinet is aware of an instance where this vulnerability was exploited, and recommends immediately validating your systems against the following indicator of compromise in the device's logs:

user="Local_Process_Access" 

Please contact customer support for assistance.

 

UPDATE: Fortinet is aware of instances where this vulnerability was exploited to download the config file from the targeted devices, and to add a malicious super_admin account called  "fortigate-tech-support":

# show system admin
edit "fortigate-tech-support"
set accprofile "super_admin"
set vdom "root"
set password ENC [...]
next

Please contact customer support for assistance.

 

Workaround:

FortiOS:

Disable HTTP/HTTPS administrative interface

OR

Limit IP addresses that can reach the administrative interface:

config firewall address

edit "my_allowed_addresses"

set subnet <MY IP> <MY SUBNET>

end

Then create an Address Group:

config firewall addrgrp

edit "MGMT_IPs"

set member "my_allowed_addresses"

end

Create the Local in Policy to restrict access only to the predefined group on management interface (here: port1):

config firewall local-in-policy

edit 1

set intf port1

set srcaddr "MGMT_IPs"

set dstaddr "all"

set action accept

set service HTTPS HTTP

set schedule "always"

set status enable

next

edit 2

set intf "any"

set srcaddr "all"

set dstaddr "all"

set action deny

set service HTTPS HTTP

set schedule "always"

set status enable

end

If using non default ports, create appropriate service object for GUI administrative access:

config firewall service custom

edit GUI_HTTPS

set tcp-portrange <admin-sport>

next

edit GUI_HTTP

set tcp-portrange <admin-port>

end

Use these objects instead of "HTTPS HTTP "in the local-in policy 1 and 2 below.

UPDATE: When using an HA reserved management interface, the local in policy needs to be configured slightly differently - please see: https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-configure-a-local-in-policy-on-a-HA/ta-p/222005

Please contact customer support for assistance.

 

FortiProxy:

Disable HTTP/HTTPS administrative interface

OR

For FortiProxy VM all versions or FortiProxy appliance 7.0.6:

Limit IP addresses that can reach the administrative interface (here: port1):

config system interface

edit port1

set dedicated-to management

set trust-ip-1 <MY IP> <MY SUBNET>

end

Please contact customer support for assistance.

 

FortiSwitchManager:

DIsable HTTP/HTTPS administrative interface

Please contact customer support for assistance.

Affected Products

FortiOS versions 5.x, 6.x are NOT impacted.
FortiOS version 7.2.0 through 7.2.1
FortiOS version 7.0.0 through 7.0.6
FortiProxy version 7.2.0
FortiProxy version 7.0.0 through 7.0.6
FortiSwitchManager version 7.2.0
FortiSwitchManager version 7.0.0

Solutions

Please upgrade to FortiOS version 7.2.2 or above
Please upgrade to FortiOS version 7.0.7 or above
Please upgrade to FortiProxy version 7.2.1 or above
Please upgrade to FortiProxy version 7.0.7 or above
Please upgrade to FortiSwitchManager version 7.2.1 or above
Please upgrade to FortiSwitchManager version 7.0.1 or above

Please upgrade to FortiOS version 7.0.5 B8001 or above for FG6000F and 7000E/F series platforms