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Forum Discussion

SIEM_281457's avatar
SIEM_281457
Icon for Nimbostratus rankNimbostratus
Jul 26, 2016

Illegal meta character in value

How to fine tune the "Illegal meta character in value" However the device custom string is "filenetservice" and in some cases its Exchange asm policy. please suggest me how to finetune this alert.  ...
application delivery
ASM Advanced WAF
Hannes_Rapp's avatar
Hannes_Rapp
Icon for Nimbostratus rankNimbostratus
Jul 26, 2016

Security -> Application Security -> Parameters -> Character Set -> Parameter Value -> Select "meta characters only" -> Disallow/Allow individual meta characters as needed

To find out which meta characters are causing the violations, you must check your ASM request/blocking logs.

Hannes_Rapp's avatar
Hannes_Rapp
Icon for Nimbostratus rankNimbostratus
Jul 26, 2016

Provide them the full request log for an investigation. They can pick the solution they prefer themselves. One option is to allow the conflicting meta-character to exist in parameter value. This solution is applicable if they conclude there's no chance the request could be malicious.