the current screensaver binary in the file system or Registry can therefore elevate privileges. In certain versions of the Linux kernel it was possible to write a program that would set its current directory to /etc/cron.d, request that a core dump be performed in case it crashes and then have itself killed by another process. The core dump file would have been placed at the program's current directory, that is, /etc/cron.d, and cron would have treated it as a text file instructing it to run programs on schedule. Because the contents of the file would be under attacker's control, the attacker would be able to execute any program with root privileges. Cross Zone Scripting is a type of privilege escalation attack in which a website subverts the security model of web browsers, thus allowing it to run malicious code on client computers. There are also situations where an application can use other high privilege services and has incorrect assumptions about how a client could manipulate its use of these services. An application that can execute Command line or shell commands could have a Shell Injection vulnerability if it uses unvalidated input as part of an executed command. An attacker would then be able to run system commands using the application's privileges. Texas Instruments calculators (particularly the TI-85 and TI-82) were originally designed to use only interpreted programs written in dialects of TI-BASIC; however, after users discovered bugs that could be exploited to allow native Z-80 code to run on the calculator hardware, TI released programming data to support third-party development. (This did not carry on to the ARM-based TI-Nspire, for which jailbreaks using Ndless have been found but are still actively fought against by Texas Instruments.) Some versions of the iPhone allow an unauthorised user to access the phone while it is locked. Jailbreaking In computer security, jailbreaking is defined as the act of removing limitations that a vendor attempted to hard-code into its software or services. A common example is the use of toolsets to break out of a chroot or jail in UNIX-like operating systems or bypassing digital rights management (DRM). In the former case, it allows the user to see files outside of the filesystem that the administrator intends to make available to the application or user in question. In the context of DRM, this allows the user to run arbitrarily defined code on devices with DRM