postgres OOB sqli failure

[ASKWares]

What's the problem (or question)?

Why sqlmap tells me
[09:55:27] [ERROR] data retrieval through DNS channel failed. Turning off DNS exfiltration support

i found a timebased sqli with dbms
PostgreSQL 9.1.24lts2 on i686-pc-linux-gnu, compiled by gcc (Debian 4.7.2-5) 4.7.2, 32-bit

worked as timebased & stacked queries , and i checked it manualy

and i've read your paper about oob sql injection attack and dns exfiltration
but when i try to send the sql query you mentioned in the paper which i don't know if it compatible with postgres 9.1 or not , it doesn't work, so i decide to ask you about this matter , because no one mention it except you , and all the papers and posts are copy of your original paper

thank you for your efforts

Do you have an idea for a solution?

How can we reproduce the issue?

What are the running context details?

• Installation method (e.g. pip, apt-get, git clone or zip/tar.gz):
• Client OS (e.g. Microsoft Windows 10)
• Program version (python sqlmap.py --version or sqlmap --version depending on installation):
• Target DBMS (e.g. Microsoft SQL Server):
• Detected WAF/IDS/IPS protection (e.g. ModSecurity or unknown):
• SQLi techniques found by sqlmap (e.g. error-based and boolean-based blind):
• Results of manual target assessment (e.g. found that the payload query=test' AND 4113 IN ((SELECT 'foobar'))-- qKLV works):
• Relevant console output (if any):
• Exception traceback (if any):

[stamparm]

Read the (e.g.) footnote 7 at that same paper: Oracle is only DBMS which doesn't need UNC file path formatting for provoking DNS requests, making attacks usable on both Windows and Linux back-end platforms. Also, if you take a look into PostgreSQL's example (in that same paper) you'll see that only Windows form is being presented.

Anyway, your Linux target does not support resolving of UNC paths (used in PostgreSQL DNS OOB case), hence, DNS OOB fails