Remote exploitation of a heap overflow vulnerability in ClamAV versions below 0.88.4 could allow execution of arbitrary code or cause a denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/49229/clamav_upx_heap.txt
Source: https://packetstormsecurity.com/files/49229/clamav_upx_heap.txt.html