According to Symantec the first exploitation of the vulnerability was discovered on 2009-01-27.
Vulnerable component: Windows
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-190 - Integer Overflow or Wraparound
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The weakness exists due to integer overflow in GDI+ when handling PNG image file. A remote attacker can create a specially crafted PNG image file, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system with privileges of the current user.
Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.
Note: according to reports this vulnerability was being actively exploited before Microsoft issued security patch.