Widely used software with key vulnerability sends cyber defenders scrambling

An illustration picture shows a projection of binary code on a man holding a laptop computer, in an office in Warsaw June 24, 2013. REUTERS/Kacper Pempel/File Photo

WASHINGTON (Reuters) - A newly discovered vulnerability in a widely used software library is causing mayhem on the internet, forcing cyber defenders to scramble as hackers rush to exploit the weakness.

The vulnerability, known as Log4j, comes from a popular open source product that helps software developers track changes in applications that they build. It is so popular and embedded across many companies' programs that security executives expect widespread abuse.