The results mean that DR Congo sit top of Group B on six points while Angola are eliminated after two defeats.
Cameroon know a draw in their final match against DR Congo on Monday will be enough for them to go through.
Only a big win for Ethiopia against Angola coupled with a Cameroon loss gives them any chance of
Cameroon had the better of the first half, which was held-up for 10 minutes because of floodlight failure, while Ethiopia improved after the break.
However it was a dull encounter in Huye after the earlier game when DR Congo raced into a 3-0 lead by half-time against neighbours Angola.
Gelson and Yano hit back for Angola but in between those goals Merveille Bope struck DR Congo's fourth.
DR Congo have now scored 7 goals at the tournament after their 3-0 win over Ethiopia, who are yet to score in Rwanda.
Cameroon won their opening match 1-0 against Angola
Credit: BBC