[gjariolg1657]

I am pentesting sql injection using sqlmap.
I can get db name, but I can't retrieve tables in that db.
The dbms and db name are correct.

////////////////////////////////////////
back-end DBMS: MySQL 4
[WARNING] information_schema not available, back-end DBMS is MySQL < 5.0
////////////////////////////////////////

How can I solve this?

[pizza500]

you cant ... sqlmap ony "guess" the table names from a predefined list

[Peter Hansen]

tamper scripts, maybe there is a waf involved

[frank3nstien]

Could be a WAF, Try using Url encoding --tamper charencode which might will work to bypass WAF

Which work in backend like this :
SELECT FIELD FROM TABLE to %53%45%4C%45%43%54%20%46%49%45%4C%44%20%46%52%4F%4D%20%54%41%42%4C%45