Kwesi Appiah's side could only manage a 2-2 draw against Benin in their opening game and they were frustrated again versus a Cameroon side who move on to four points at the group's summit.
Ghana came agonisingly close to sealing all three points in the closing stages when substitute Owusu Kwabena's powerful drive crashed back off the crossbar.
However, they will now be under pressure when they face Guinea-Bissau on Tuesday in their final group game. Cameroon, meanwhile, are in pole position to qualify for the last 16 and face Benin on the same day.
Ghana looked sharper from the outset and should have forged ahead after nine minutes but Thomas Partey blazed over from 12 yards after being picked out by Jonathan Mensah.
That was followed soon after by a Christian Atsu effort from distance that fizzed past Andre Onana's left-hand post.
Cameroon belatedly woke from their slumber and twice tested Richard Ofori in the final 10 minutes of the first half.
First, the Black Stars goalkeeper blocked Clinton N'Jie's fierce drive at his near post and he then produced a stunning save to paw away Christian Bassogog's drive from 10 yards after a flowing move had carved his defence open.
Ghana started the second half brightly, with Mubarak Wakaso drilling a strike from distance narrowly past Onana's left-hand upright.
They soon fizzled out, though, with both sides lacking any kind of fluidity in a desperately poor second half.
Kwabena came so close to securing a precious win three minutes from time, picking up Jean-Armel Kana-Biyik's loose ball on the halfway line and charging forward before thundering an effort against Onana's crossbar, but, in truth, a winner for either side would have been scarcely deserved.