WebKit, as used in Apple Safari before 5.0.6, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site, a different vulnerability than other WebKit CVEs listed in APPLE-SA-2011-07-20-1.
http://support.apple.com/kb/HT4981
http://support.apple.com/kb/HT4808
http://lists.apple.com/archives/security-announce/2011//Jul/msg00002.html
http://lists.apple.com/archives/Security-announce/2011//Oct/msg00000.html