An exploitable stack-based buffer overflow vulnerability exists in the JPEG parser of Atlantis Word Processor, version 220.127.116.11. A specially crafted image embedded within a document can cause a length to be miscalculated and underflow. This length is then treated as unsigned and then used in a copying operation. Due to the length underflow, the application will then write outside the bounds of a stack buffer, resulting in a buffer overflow. An attacker must convince a victim to open a document in order to trigger this vulnerability.