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Q-142: openssh Security Update
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ESCAPESHELLCMD(3) 1 ESCAPESHELLCMD(3) escapeshellcmd - Escape shell metacharacters SYNOPSIS
string escapeshellcmd (string $command) DESCRIPTION
escapeshellcmd(3) escapes any characters in a string that might be used to trick a shell command into executing arbitrary commands. This function should be used to make sure that any data coming from user input is escaped before this data is passed to the exec(3) or system(3) functions, or to the backtick operator. Following characters are preceded by a backslash: #&;`|*?~<>^()[]{}$, x0A and xFF. ' and " are escaped only if they are not paired. In Windows, all these characters plus % are replaced by a space instead. PARAMETERS
o $command - The command that will be escaped. RETURN VALUES
The escaped string. EXAMPLES
Example #1 escapeshellcmd(3) example <?php // We allow arbitrary number of arguments intentionally here. $command = './configure '.$_POST['configure_options']; $escaped_command = escapeshellcmd($command); system($escaped_command); ?> Warning escapeshellcmd(3) should be used on the whole command string, and it still allows the attacker to pass arbitrary number of argu- ments. For escaping a single argument escapeshellarg(3) should be used instead. SEE ALSO
escapeshellarg(3), exec(3), popen(3), system(3), backtick operator. PHP Documentation Group ESCAPESHELLCMD(3)
