This Metasploit module exploits a flaw in the Web Start component of the Sun Java Runtime Environment. Parameters intial-heap-size and max-heap-size in a JNLP file can contain a double quote which is not properly sanitized when creating the command line for javaw.exe. This allows the injection of the -XXaltjvm option to load a jvm.dll from a remote UNC path into the java process. Thus an attacker can execute arbitrary code in the context of a browser user. This flaw was fixed in Oct. 2012 and affects JRE <= 1.6.35 and <= 1.7.07. In order for this module to work, it must be ran as root on a server that does not serve SMB. Additionally, the target host must have the WebClient service (WebDAV Mini-Redirector) enabled. Alternatively an UNC path containing a jvm.dll can be specified with an own SMB server.

CVE-2012-1533