Of course i did check logs and seen which particular cookie is problematic, but i dont understand why is it.. I guess i'll need to get deeply into this - how forti is processing it. There must be sth that couses such errors. I suspecting at first " track lost".
Its weird for me that forti couldn't check such cookie, so it will not prevent poisoning.
Yes, its happening for all users, I was also thinking that maybe there is some expiration date on destination server? i did enable expiration of cookie for 15min - just for testing but no special result i got :)
As per FortiWeb Administration Guide on Cookie Security "Signed" mode, FortiWeb will track cookies value responded by web server in the first HTTP/S request from the client, hash it and track if there is any tampering in the following requests.
The cookie name mentioned (AMP_899c7e29a9) value may have changed and FortiWeb took action according to configured action in the cookie security policy. Please refer below for possible solutions;
1. Change to "Encrypted" mode - works in some cases where cookies value keeps on changing(not preferred if you would like to prevent cookie poisoning attack) 2. Do exceptions according to the cookie name
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.