With Uzbekistan losing 1-0 in China, the Koreans would have sealed Group A's second automatic berth for Russia but could find no way past an impregnable Iran, who have not conceded a goal in 12 straight World Cup qualifiers dating back to November 2015.
Korea's Jang Hyun-soo came closest to breaking the deadlock in the 19th minute at Seoul World Cup Stadium when his glancing header from inside the six yard box dropped inches wide of Ali Beiranvand's left-hand post.
While Swansea City midfielder Ki Sung-yueng was not judged fit enough to play, Korea's talismanic wide man Son Heung-min was in the line-up but was given little time or space by Iran's defence.
The game took a nasty turn in the 50th minute when Iran's Saeid Ezatolahi was shown a red card for stamping on the head of Korean defender Kim Min-jae.
With the man advantage and some 60,000 fans roaring them on, the Koreans threw men forward in search of the winner but Iran held firm until the final whistle.
The result sees Korea remain in second place on 14 points behind already qualified Iran, with Syria and Uzbekistan two points behind.
The Koreans travel to Tashkent to play Uzbekistan in their final qualifier on Sept. 5, while Syria take on Iran in Tehran.
(Writing by Peter Rutherford; Editing by Nick Mulvenney)
