What is GHOST bug?
The GHOST bug is a security hole in the GNU C Library (glibc) of the Linux operating system. It was discovered by the security company Qualys in January 2015. However, according to Trend Micro, the affected library was repaired back in May 2013.
The error can be found in the functions 'gethostbyname' and 'gethostbyname2' of the glibc library. These functions are used to resolve a domain name to its IP address. The GHOST bug can be exploited to create a buffer overflow, a vulnerability that enables an attacker to execute arbitrary code on an affected system so that the attacker can control the system.
Since the bug was fixed in 2013, newer systems are not affected by this bug. In addition, these functions are already obsolete because they have been replaced by the 'getaddrinfo' function.