Integer underflow in QuickDraw Manager in Apple Mac OS X 10.4.11 and 10.5 before 10.5.7, and Apple QuickTime before 7.6.2, allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a PICT image with a crafted 0x77 Poly tag and a crafted length field, which triggers a heap-based buffer overflow.