BusyBox provides a single binary that includes versions of a large number of system commands, including a shell. This can be very useful for recovering from certain types of system failures, particularly those involving broken shared libraries. A buffer underflow flaw was found in the way the uncompress utility of BusyBox expanded certain archive files compressed using Lempel-Ziv compression. If a user were tricked into expanding a specially-crafted archive file with uncompress, it could cause BusyBox to crash or, potentially, execute arbitrary code with the privileges of the user running BusyBox. The BusyBox DHCP client, udhcpc, did not sufficiently sanitize certain options provided in DHCP server replies, such as the client hostname. A malicious DHCP server could send such an option with a specially-crafted value to a DHCP client. If this option"s value was saved on the client system, and then later insecurely evaluated by a process that assumes the option is trusted, it could lead to arbitrary code execution with the privileges of that process. Note: udhcpc is not used on Red Hat Enterprise Linux by default, and no DHCP client script is provided with the busybox packages. This update also fixes the following bugs: * Prior to this update, the cp command wrongly returned the exit code 0 to indicate success if a device ran out of space while attempting to copy files of more than 4 gigabytes. This update modifies BusyBox, so that in such situations, the exit code 1 is returned. Now, the cp command shows correctly whether a process failed. * Prior to this update, the findfs command failed to check all existing block devices on a system with thousands of block device nodes in "/dev/". This update modifies BusyBox so that findfs checks all block devices even in this case. All users of busybox are advised to upgrade to these updated packages, which correct these issues.