Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

IMAP Configure Options

Name	Default	Changeable	Changelog
imap.enable_insecure_rsh	"0"	INI_SYSTEM	Available as of PHP 7.1.25, 7.2.13 and 7.3.0. Formerly, it was implicitly enabled.

For further details and definitions of the INI_* modes, see the Where a configuration setting may be set.

Here's a short explanation of the configuration directives.

imap.enable_insecure_rsh bool

Establishing a connection to a server may invoke rsh or ssh commands, unless this php.ini option is disabled.

Warning

Neither PHP nor the IMAP library filter mailbox names before passing them to rsh or ssh commands, thus passing untrusted data to this function without disabling this php.ini option is insecure.