I created a custom vulnerability signature that helps to detect and block the recently discovered Joomla RCE zero day which has since been patched by the vendor. I've opened a case with an engineer and he suggesed some additional protections until an official signature is released. The engineer suggested I post it here so that other people may benefit.
It checks for the following http headers in a GET request:
I don't see an option to upload the .xml so here is the full xml code, sorry for the length:
<vulnerability-threat version="6.1.0"> <entry name="41001"> <signature> <standard> <entry name="Suspicious HTTP Header"> <and-condition> <entry name="And Condition 1"> <or-condition> <entry name="Or Condition 1"> <operator> <pattern-match> <qualifier> <entry name="http-method"> <value>GET</value> </entry> </qualifier> <pattern>((JDatabaseDriverMysqli)|(JSimplepieFactory)|(disconnectHandlers))</pattern> <context>http-req-headers</context> </pattern-match> </operator> </entry> <entry name="Or Condition 2"> <operator> <pattern-match> <qualifier> <entry name="http-method"> <value>GET</value> </entry> </qualifier> <pattern>eval(base64_decode($_POST))</pattern> <context>http-req-headers</context> </pattern-match> </operator> </entry> </or-condition> </entry> </and-condition> <order-free>no</order-free> <scope>protocol-data-unit</scope> <comment>User agent strings identified in the reference link</comment> </entry> </standard> </signature> <default-action> <drop-packets/> </default-action> <cve> <member>CVE-2015-8562</member> </cve> <reference> <member>https://wp.me/p3AjUX-u58</member> </reference> <vendor> <member>Joomla</member> </vendor> <threatname>Joomla CVE-2015-8562</threatname> <severity>critical</severity> <direction>client2server</direction> <comment>Remote Code Execution Vulnerability. This signature is only a band-aid per the link in the reference below.</comment> <affected-host> <server>yes</server> </affected-host> </entry> </vulnerability-threat>
Solved! Go to Solution.
Click Accept as Solution to acknowledge that the answer to your question has been provided.
The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!
These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the Live Community as a whole!
The Live Community thanks you for your participation!