Apple released its OS X Bash Update 1.0 for OS X Mavericks, Mountain Lion, and Lion earlier this week to address potential “Bash bug,” or Shellshock, vulnerabilities in its devices.

Apple previously told iMore its systems were safe “by default” from the bug and were only vulnerable if users configured advanced UNIX services. On the OS X Mavericks system, this update upgrades the Bash shell from 3.2.51 to version 3.2.53, which users could do on their own if they wanted, according to Ars Technica.

Apple will not release an individual patch for users running the current OS X Yosemite developer or public beta builds, but the bug will be addressed in future software.

Attackers have already begun experimenting with the bug, and some researchers have reported the discovery of multiple botnets.