Last week, Internet Systems Consortium (ICS) released a fix for a critical bug in BIND DNS software, which could affect the stability of the internet in the whole world.

BIND is the most popular DNS software on the web and is the default on Unix-based systems.

Internet Systems Consortium (ISC), which develops BIND said:

“As this development significantly increases the potential risk that this vulnerability will be exploited by those with a mind to do so, please take steps to patch or upgrade to a secure version as soon as possible.”

It could threaten the smooth running of internet services as the bug let hackers to launch denial-of-service (DOS) attacks on websites with a simple command and potentially force them to go offline. However, normal internet users are not likely to be much affected. The bug in BIND DNS software affects versions of BIND 9, from BIND 9.1.0 to BIND 9.10.2-P2.

The vulnerability affects a feature called TKEY, classified as expendable by security expert Robert Graham. The BIND system cannot handle malformed packets in order of the function. These packages can be created easily and can be sent remotely to vulnerable servers as a kind of denial-of-service attack and knock them down.

Daniel Cid, CTO and founder of the security company Sucuri, wrote in a blog post regarding the bug in BIND DNS software:

“A few of our clients, in different industries, had their DNS servers crashed because of it. Because of its severity we’ve been actively monitoring to see when the exploit would be live. We can confirm that the attacks have begun. DNS is one of the most critical parts of the Internet infrastructure, so having your DNS go down, it also means your email, HTTP and all other services will be unavailable.”

The patch for the bug in BIND DNS software has already been released in all major Linux distributions, and administrators must install it manually and restart the server to complete the process.