Improper Restriction of Operations within the Bounds of a Memory Buffer
The Load_SBit_Png function in sfnt/pngshim.c in FreeType before 2.5.4 does not restrict the rows and pitch values of PNG data, which allows remote attackers to cause a denial of service (integer overflow and heap-based buffer overflow) or possibly have unspecified other impact by embedding a PNG file in a .ttf font file.
CWE-119 - Buffer Overflow
Buffer overflow attacks involve data transit and operations exceeding the restricted memory buffer, thereby corrupting or overwriting data in adjacent memory locations. Such overflow allows the attacker to run arbitrary code or manipulate the existing code to cause privilege escalation, data breach, denial of service, system crash and even complete system compromise. Given that languages such as C and C++ lack default safeguards against overwriting or accessing data in their memory, applications utilizing these languages are most susceptible to buffer overflows attacks.