As if consumers weren’t already suffering from breach fatigue: Experts warn that attackers are exploiting a critical, newly-disclosed security vulnerability present in countless networks and Web sites that rely on Unix and Linux operating systems. Experts say the flaw, dubbed “Shellshock,” is so intertwined with the modern Internet that it could prove challenging to fix, and in the short run is likely to put millions of networks and countless consumer records at risk of compromise. The bug is being compared to the recent Heartbleed vulnerability because of its ubiquity and sheer potential for causing havoc on Internet-connected systems — particularly Web sites