An information disclosure vulnerability exists in the way that the Windows Graphics Device Interface (GDI) handles objects in memory, allowing an attacker to retrieve information from a targeted system. An attacker who successfully exploited this vulnerability could use the retrieved information to circumvent Address Space Layout Randomization (ASLR) in Windows, which helps guard against a broad class of vulnerabilities. By itself, the information disclosure does not allow arbitrary code execution; however, it could allow arbitrary code to be run if the attacker uses it in combination with another vulnerability, such as a remote code execution vulnerability, that is capable of leveraging the ASLR circumvention.
To exploit this vulnerability, an attacker would have to log on to an affected system and run a specially crafted application.
The security update addresses the vulnerability, and helps protect the integrity of the ASLR security feature, by correcting how GDI handles memory addresses.