About OS X bash Update 1.0

This document describes the security content of OS X bash Update 1.0.

This update can be downloaded from the Apple Support website.

For the protection of our customers, Apple does not disclose, discuss, or confirm security issues until a full investigation has occurred and any necessary patches or releases are available. To learn more about Apple Product Security, see the Apple Product Security website.

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Where possible, CVE IDs are used to reference the vulnerabilities for further information.

To learn about other Security Updates, see Apple Security Updates.

OS X bash Update 1.0

• Bash

  Available for: OS X Lion v10.7.5, OS X Lion Server v10.7.5, OS X Mountain Lion v10.8.5, OS X Mavericks v10.9.5

  Impact: In certain configurations, a remote attacker may be able to execute arbitrary shell commands

  Description: An issue existed in Bash's parsing of environment variables. This issue was addressed through improved environment variable parsing by better detecting the end of the function statement.

  This update also incorporated the suggested CVE-2014-7169 change, which resets the parser state.

  In addition, this update added a new namespace for exported functions by creating a function decorator to prevent unintended header passthrough to Bash. The names of all environment variables that introduce function definitions are required to have a prefix "__BASH_FUNC<" and suffix ">()" to prevent unintended function passing via HTTP headers.

  CVE-ID

  CVE-2014-6271 : Stephane Chazelas

  CVE-2014-7169 : Tavis Ormandy