According to Symantec the first exploitation of the vulnerability was discovered on 2009-03-19.
Vulnerable component: Ichitaro
CVSSv3 score: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C
CWE-ID: CWE-122 - Heap-based Buffer Overflow
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The weakness exists due to heap-based buffer overflow when handling malformed files. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the system with privileges of the current user.
Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.
Note: the vulnerability was being actively exploited.