Added some info on problems encountered during testing.

Author: bwatters-r7

documentation/modules/exploit/linux/http/centreon_useralias_exec.md

@@ -34,6 +34,25 @@ cd nagios-plugins-2.1.1/
 ./configure
 make
 sudo make install
+```
+  5.1 If during make, you get an sslv3 method not found error (https://support.nagios.com/forum/viewtopic.php?f=35&t=36601&p=168235&hilit=SSLv3#p168235)
+```
+--- plugins/sslutils.c.orig   2016-01-14 20:02:06.419867000 +0100
++++ plugins/sslutils.c   2016-01-14 20:01:36.091492000 +0100
+@@ -70,8 +70,13 @@
+#endif
+      break;
+   case 3: /* SSLv3 protocol */
++#if defined(OPENSSL_NO_SSL3)
++      printf(("%s\n", _("CRITICAL - SSL protocol version 3 is not supported by your SSL library.")));
++      return STATE_CRITICAL;
++#else
+      method = SSLv3_client_method();
+      ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_TLSv1;
++#endif
+      break;
+   default: /* Unsupported */
+      printf("%s\n", _("CRITICAL - Unsupported SSL protocol version."));
 ```
   6. Install [Centreon clib](https://documentation.centreon.com/docs/centreon-clib/en/latest/installation/index.html)
 ```
@@ -67,6 +86,7 @@ sudo make install
 sudo mkdir /var/log/centreon-engine
 cd ~
 sudo pear install XML_RPC-1.4.5
+(may need to install php-xml)
 wget https://www.exploit-db.com/apps/bf269a17dd99215e6dc5d7755b521c21-centreon-2.5.3.tar.gz
 tar vxf bf269a17dd99215e6dc5d7755b521c21-centreon-2.5.3.tar.gz
 cd centreon-2.5.3
@@ -188,4 +208,4 @@ Just a standard run.
     www-data
     uname -a
     Linux centreon 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
-```
+```