Forum Discussion
By default Parse parameters is checked. By unchecking parse parameters it allows you to define metacharecters, signatures, etc.
https://support.f5.com/kb/en-us/products/big-ip_asm/releasenotes/product/relnote-asm-13-0-0.html
JSON Support and Granularity Improvements
The JSON profile now includes a new flag: parse parameters. The flag is ON by default. The parameters will be extracted if the flag is set and a JSON profile is attached to the URL or parameter. Any sensitive data, attack signatures or meta character exclusions that are defined in the JSON profile are now enforced with any similar items defined in parameters. The entire JSON profile is parsed and tokenized to parameters. The enforcement moves to the parameters and is done according to the configuration of the wildcard or explicit entity that is matched.
- Only1masterbla1Nov 08, 2017Cirrus
JSON parameterization was introduced in 13.0. You should be able to change allowed/disallowed metacharacters on per parameter basis. Pre-13.x has a very basic JSON control. I don't have 13.x yet, your findings will be interesting.