Can I withdraw money through ATM in KSA from Paksitan's bank account?

Most banks you can withdraw while overseas but they may be a charge which can sometimes be quite large, but this does vary from bank to bank.

Every 99/100 banks support this. Although as mentioned by jomcp, additional charges like overseas charges per transaction by original bank, withdrawal fees per transaction by overseas bank, etc would be involved depending on the original banks agreements with overseas banks.

Also there would be reduced currency exchange rates. For instance, generally PKR would be converted into US Dollars and then into Saudi Riyals (Bank Rates) which you can consider as another charge. Again it can be reduced if the original bank has direct agreements with particular overseas banks.

It's costly but better to avail it in emergencies.

HTH,

Khurram.

Is there a Habib Bank ATM in Riyadh? Where exactly is that?

25-30 Riyal charges apply... if Visa or master card...or even 1 link some places

There is no Habib Bank in Riyadh. There is a branch of NCB however, on King Fahad Road opposite to Kingdom Tower.