Adobe has updated Photoshop CS4 for Mac OSX and the Windows platform to address CVE-2010-1296. A malicious .ASL, .ABR or .GRD could be used to gain access to the users system or execute arbitrary/malicious code. This would occur with the current user privileges. The attack requires the user to open the infected/malicious file. Users should update their version of CS4.
http://www.adobe.com/support/downloads/detail.jsp?ftpID=4712