Vulnerability Note VU#162308

Resin Pro improperly performs Unicode transformations

Original Release date: 23 Jul 2014 | Last revised: 23 Jul 2014

Overview

Resin Pro 4.0.39 and possibly earlier versions improperly performs Unicode transformations.

Description

CWE-20: Improper Input Validation

Resin Pro 4.0.39 and possibly earlier versions perform incorrect Unicode transformations on output to HTTP responses for ISO-8859-1. This allows an attacker to bypass filtering/encoding/validation done prior to the output transformation. An attacker can use specially crafted input characters on pages that by default respond with ISO-8859-1 (or can be forced to use it) to bypass filtering/encoding/validation done prior to the output transformation.

It should be noted that Resin's default encoding (charset) is ISO-8859-1.

Impact

A remote unauthenticated attacker may be able to perform XSS, Open Redirect, and other attacks that depend on the logic being enforced prior to the transformation and bypassed due to this vulnerability.

Solution

Apply an Update

Resin Pro 4.0.40 has been released to address this vulnerability. If you are unable to upgrade, please consider the following workaround.

Restrict Access

As a general good security practice, only allow connections from trusted hosts and networks. Note that restricting access does not prevent XSS or CSRF attacks since the attack comes as an HTTP request from a legitimate user's host. Restricting access would prevent an attacker from accessing the web interface using stolen credentials from a blocked network location.

Restrict content to always use UTF-8 (or other safe charsets)

Using HttpServletResponse.setContentType() to set the response charset to UTF-8. For example: response.setContentType("text/html;charset=UTF-8");

According to Caucho's base documentation, it is possible to change the system wide encoding to use UTF-8 with a single directive.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
Caucho TechnologyAffected27 Feb 201423 Jun 2014
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N
Temporal 4.5 E:POC/RL:OF/RC:C
Environmental 1.3 CDP:L/TD:L/CR:ND/IR:ND/AR:ND

References

Credit

Thanks to Yoel Gluck and Angelo Prado from Salesforce.com's Product Security team for reporting this vulnerability

This document was written by Chris King.

Other Information

  • CVE IDs: CVE-2014-2966
  • Date Public: 23 Jul 2014
  • Date First Published: 23 Jul 2014
  • Date Last Updated: 23 Jul 2014
  • Document Revision: 19

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