Re: PHP imap_open() script injection

[Salvatore Bonaccorso <carnil () debian org>]

Hi,

On Thu, Nov 22, 2018 at 09:02:14PM +0100, Hanno Böck wrote:
> Hi,
>
> This was apparently posted on some russian forum recently and then
> re-posted to github:
> https://antichat.com/threads/463395/#post-4254681
> https://github.com/Bo0oM/PHP_imap_open_exploit/blob/master/exploit.php
>
> PoC code:
> $server = "x -oProxyCommand=echo\tZWNobyAnMTIzNDU2Nzg5MCc+L3RtcC90ZXN0MDAwMQo=|base64\t-d|sh}";
> imap_open('{'.$server.':143/imap}INBOX', '', '') or die("\n\nError: ".imap_last_error());
>
> It's pretty self explaining, it seems imap_open() will pass things to
> ssh and this is vulnerable to a shell injection.
>
> Impact would be mostly relevant if someone has some imap functionality
> where a user can define a custom imap server. (Though it might also be
> used as a bypass for environments where exec() and similar functions
> are restricted.)
>
> I reported it to upstream PHP a few days ago, it was closed as a
> duplicate, so it seems they already knew about it. It's unfixed in
> current versions.

CVE-2018-19518 has been assigned by MITRE for this issue.

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-19518

Regards,
Salvatore