University of Washington IMAP Toolkit 2007f on UNIX, as used in imap_open() in PHP and other products, launches an rsh command (by means of the imap_rimap function in c-client/imap4r1.c and the tcp_aopen function in osdep/unix/tcp_unix.c) without preventing argument injection, which might allow remote attackers to execute arbitrary OS commands if the IMAP server name is untrusted input (e.g., entered by a user of a web application) and if rsh has been replaced by a program with different argument semantics. For example, if rsh is a link to ssh (as seen on Debian and Ubuntu systems), then the attack can use an IMAP server name containing a "-oProxyCommand" argument.

PHP-IMAP is a wrapper for common IMAP communication without the need to have the php-imap module installed / enabled. Prior to version 5.3.0, an unsanitized attachment filename allows any unauthenticated user to leverage a directory traversal vulnerability, which results in a remote code execution vulnerability. Every application that stores attachments with `Attachment::save()` without providing a `$filename` or passing unsanitized user input is affected by this attack. An attacker can send an email with a malicious attachment to the inbox, which gets crawled with `webklex/php-imap` or `webklex/laravel-imap`. Prerequisite for the vulnerability is that the script stores the attachments without providing a `$filename`, or providing an unsanitized `$filename`, in `src/Attachment::save(string $path, string $filename = null)`. In this case, where no `$filename` gets passed into the `Attachment::save()` method, the package would use a series of unsanitized and insecure input values from t…

The map_yp_alias function in functions/imap_general.php in SquirrelMail before 1.4.19-1 on Debian GNU/Linux, and possibly other operating systems and versions, allows remote attackers to execute arbitrary commands via shell metacharacters in a username string that is used by the ypmatch program. NOTE: this issue exists because of an incomplete fix for CVE-2009-1579.