What internet vulnerability 'bug' was announced (in April 2014) to have existed in 17% of the world's web servers since end-2011?
Shellshock (software bug) botnets of compromised computers to perform distributed denial-of-service attacks and vulnerability scanning. Security companies recorded millions of attacks and probes related to the bug in the days following the disclosure. Shellshock could potentially compromise millions of unpatched servers and other systems. Accordingly, it has been compared to the Heartbleed bug in its severity. The Shellshock bug affects Bash, a program that various Unix-based systems use to execute command lines and command scripts. It is often installed as the system's default command-line interface. Analysis of the source code history of Bash shows the bugs had existed since Bash version 1.03 released
Internet Explorer an alternate browser until the bug is fixed. The UK National Computer Emergency Response Team (CERT-UK) published an advisory announcing similar concerns and for users to take the additional step of ensuring their antivirus software is up-to-date. Symantec, a cyber security firm, confirmed that "the vulnerability crashes Internet Explorer on Windows XP". The vulnerability was resolved on May 1, 2014, with a security update. The adoption rate of Internet Explorer seems to be closely related to that of Microsoft Windows, as it is the default web browser that comes with Windows. Since the integration of Internet Explorer 2.0 with Windows