The Bluebirds also hit the woodwork twice while Leicester felt aggrieved after they were denied what looked a clear penalty before Cardiff keeper David Marshall produced a wonder save at the death to keep out Andy King.
The home side's first threat came from Lloyd Dyer whose clever turn gave him a glimpse of goal before Mark Kennedy came across to snuff out the danger.
Kennedy then rescued Cardiff again when he headed a dangerous inswinging corner from Martyn Waghorn off the line. Cardiff's riposte was a low drive from Jay Bothroyd which fizzed just wide.
Leicester were awarded a free-kick 20 yards in front of goal but Nolberto Solano failed to exploit the opportunity, firing straight at the keeper.
Dyer's trickery beat two defenders down the left but his cross was a fraction too strong for Waghorn. Cardiff created a great chance on 21 minutes when Bothroyd fed Michael Chopra who, with only the keeper to beat, dragged an angled shot wide of the far post.
Darcy Blake then tried his luck with an overhead kick from a half-cleared corner but Chris Weale was handily placed to make a comfortable save.
The visitors almost broke through on 39 minutes when Chris Burke whipped in a low cross for Chopra to squeeze a close-range shot against the near post.
The first action after the restart saw Jay Spearing lift a speculative drive into the crowd. Bothroyd then wasted a great chance to put the visitors in front when unmarked and from close range he headed a Kevin McNaughton cross against the bar.
Leicester hit back with Dyer finding Richie Wellens whose 25-yard low drive flew just wide before a similar effort by Waghorn lacked the venom to trouble Marshall.
Nigel Pearson made his first switch on 62 minutes when Dyer made way for Matt Fryatt.
Leicester had pleas for a clear penalty waved aside on 63 minutes when McNaughton, under pressure from Waghorn, handled a deep cross from Wellens inside the box.
But it was advantage Cardiff on 78 minutes when, from out on the right and 25 yards from goal, Whittingham curled a free-kick home in off Chris Weale's near post.
Leicester had a great opportunity to equalise on 82 minutes when Fryatt exploited a mistake by McNaughton but could then only flick the ball against the keeper.
The Foxes continued to press with Paul Gallagher placing a 16-yard shot just wide. Then, deep into stoppage time, Gallagher saw his close-range effort blocked by Mark Hudson before Marshall produced a stunning save to claw away Andy King's goalbound header from Gallagher's corner.