Windows Adobe Type Manager Font Driver (ATMFD.DLL) Memory Corruption Local Privilege Escalation (CVE-2015-2387)

1. Vulnerability Overview & Root Cause

This vulnerability (CVE-2015-2387) is an out-of-bounds write (CWE-787) vulnerability in the Adobe Type Manager Font Driver (ATMFD.DLL) running in Windows kernel mode. The root cause lies in the improper validation of input data size when parsing specially crafted OpenType Font (OTF) files. This allows an attacker-controlled payload to overwrite adjacent kernel memory structures beyond the allocated buffer boundaries.

2. Exploitation Mechanics & Attack Scenario

An attacker with local, low-privileged access executes a malicious binary or document containing a malformed font structure. When ATMFD.DLL allocates kernel pool memory to render the font, the lack of boundary checks allows the attacker to overwrite critical kernel objects or function pointers. By hijacking the execution flow, the attacker escalates privileges to SYSTEM, bypassing operating system security controls. This vulnerability has been actively exploited in the wild by advanced threat actors, leading to its inclusion in the CISA KEV catalog.

3. Infrastructure & Business Impact

Successful exploitation allows a local attacker to elevate privileges to the highest level (SYSTEM) on critical Windows infrastructure, including domain controllers and database servers. This enables full data exfiltration, installation of persistent backdoors, disabling of endpoint security agents, and subsequent lateral movement across the corporate network, posing a severe threat to business continuity.