How do I find a specific bug on Apple's Bug Reporter?
Apple's bug database is private, and as you see, you are only able to review the bugs that you submit. This has been the subject of much debate in the Apple developer community.

Open Radar is an attempt to shed light on bugs that participating developers file. It uses the same ID numbers as the real Bug Reporter system, so if the bug referred to is in Open Radar, you should be able to find it by its ID.