Heap-based buffer overflow in the get_bhead function in readfile.c in Blender BlenLoader 2.0 through 2.40pre allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via a .blend file with a negative bhead.len value, which causes less memory to be allocated than expected, possibly due to an integer overflow.
http://www.vupen.com/english/advisories/2005/3032
http://www.securityfocus.com/archive/1/419907/100/0/threaded
http://www.gentoo.org/security/en/glsa/glsa-200601-08.xml
http://www.debian.org/security/2006/dsa-1039
http://secunia.com/advisories/19754
http://secunia.com/advisories/18452