The decoder for Macromedia Shockwave Flash allows remote attackers to execute arbitrary code via a malformed SWF header that contains more data than the specified length.
http://www.securityfocus.com/bid/5430
http://www.redhat.com/support/errata/RHSA-2003-027.html
http://www.redhat.com/support/errata/RHSA-2003-026.html
http://www.macromedia.com/v1/handlers/index.cfm?ID=23293