[securitylab.ru & security.nnov] Kerio Winroute Firewall Xroxy problem

2003-11-19T00:00:00
ID SECURITYVULNS:DOC:5422
Type securityvulns
Reporter Securityvulns
Modified 2003-11-19T00:00:00

Description

Application: Kerio Winroute Firewall 5.10 Vendor: Kerio Technologies Inc. Vendor Site: http://www.kerio.com Remote: Yes Exploitable: Yes Risk level: Critical (if proxy requires authentication) Authors: Alexander Antipov & 3APA3A (aka Pig Killer) Authors Sites: http://www.securitylab.ru http://www.security.nnov.ru

Intro:

Winroute is most popular SOHO software firewall/router/Proxy solution for Windows platform.

Vulnerability:

During troubleshooting of Winroute a security related problem was discovered allowing remote website to obtain cleartext credentials (username:password) of WinRoute user.

Details:

WinRoute has extremely weak functionality as a proxy server. It doesn't rebuild request sent by browser. Instead, it only changes Proxy- related header by substituting fist character to X (So, for example, Proxy-Connection header becomes Xroxy-Connection: in outgoing request). It leads to few troubles. First, it leaks HTTP established connections. Every file (for exmple .gif, html, jpg) from web server requires separate connection resulting in performance degradation. But, of cause, security related problem is in handling Proxy-Authorization: header sent by browser. Browser sends this header with every request in a case proxy server requires authentication. This header contains base64-encoded username and password of proxy user in cleartext (NTLM and Kerberos probably is not supported by WinRoute). If WinRoute uses windows authentication this credentials contain domain account information.

As a result, any webserver visited by WinRoute user can track his proxy username and password by Xroxy-Authorization: header (X because first character is changed). For example Xroxy-Authorization: Basic dGVzdDp0ZXN0aW5n (test:testing).

Workaround:

Disable proxy authentication

Greets:

to Ink-Visitor who still awaiting for his document from Pig.

-- http://www.security.nnov.ru /\_/\ { , . } |\ +--oQQo->{ ^ }<-----+ \ | ZARAZA U 3APA3A } You know my name - look up my number (The Beatles) +-------------o66o--+ / |/