09-15-2016 01:00 PM - edited 03-10-2019 06:41 AM
I have a Cisco ASA w/FirePOWER using SourceFire module version 5.4.1. The IPS is seeing SFTP traffic and misidentifying it as an SSH_EVENT_RESPOVERFLOW intrusion event because it thinks the packets are trying to exploit a vulnerability in OpenSSH. The inline action is to drop the packets. I want to set it up so that the IPS will not drop these packets when it sees the traffic going to specific servers, but will function normally otherwise. I tried to change the SSH_EVENT_RESPOVERFLOW rule in the Rule Editor but received this message:
This preprocessor rule cannot be modified from the rule editor. If you want to modify this rule, you can change the settings in a Network Analysis policy for this preprocessor.
How can I change the preprocessor rule so that the IPS doesn't drop packets that it misidentifies as SSH_EVENT_RESPOVERFLOW intrusion events for SPECIFIC servers?
10-06-2016 12:04 AM
10-06-2016 06:23 AM
Tushar,
Cisco ended up confirming for me that there is a bug related to this and they provide me with this link:
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCva18960
They also recommended updating the VDB version in FireSIGHT. As a workaround I did create a Network Access Policy where I disabled the "Challenge-Response Buffer Overflow" pre-processor rule in the Access Control Policy for certain IP addresses. This resolved the issue.
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