Adobe Flash Player before 9.0.277.0 and 10.x before 10.1.53.64, and Adobe AIR before 2.0.2.12610, allows remote web servers to cause a denial of service (NULL pointer dereference and browser crash) by returning a different response when an HTTP request is sent a second time, as demonstrated by two responses that provide SWF files with different SWF version numbers.

Adobe Flash Player 9.0.115.0 and earlier, and 8.0.39.0 and earlier, allows remote attackers to execute arbitrary code via an SWF file with a modified DeclareFunction2 Actionscript tag, which prevents an object from being instantiated properly.