ips_kernel/class_upload.php in Invision Power Board (IPB or IP.Board) 2.3.1 up to 20070912 allows remote attackers to upload arbitrary script files with crafted image filenames to uploads/, where they are saved with a .txt extension and are not executable.  NOTE: there are limited usage scenarios under which this would be a vulnerability, but it is being tracked by CVE since the vendor has stated it is security-relevant.