Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

[R1] Microsoft Forefront Unified Access Gateway Multiple Vulnerabilities

Medium

Synopsis

Tenable discovered three vulnerabilities:

#1 Microsoft Forefront Unified Access Gateway contains a flaw in the ExcelTable.asp script that is triggered as CRLF (Carriage Return and Line Feed) character sequences are not properly sanitized before being included in HTTP responses. This allows a remote attacker to inject additional headers via the 'title' parameter into responses to conduct HTTP response splitting attacks. Note that the trailing .xls extension can be removed by passing an encoded NULL byte in the URL.

#2 Microsoft Forefront Unified Access Gateway contains a flaw that allows a reflected cross-site scripting (XSS) attack. This flaw exists because the ExcelTable.asp script does not validate input to the tableData parameter before returning it to users. This may allow a context-dependent attacker to create a specially crafted request that would execute arbitrary script code in a user's browser session within the trust relationship between their browser and the server.

#3 Microsoft Forefront Unified Access Gateway contains a flaw that allows a reflected cross-site scripting (XSS) attack. This flaw exists because the Default.asp script does not validate input to the URI before returning it to users. This may allow a context-dependent attacker to create a specially crafted request that would execute arbitrary script code in a user's browser session within the trust relationship between their browser and the server. A proof-of-concept is provided below.

Solution

Microsoft has released a patch to address these issues.

Proof of Concept

http://[target]:50002/Default.asp?"><frame/src="javascript:alert('xss')

Disclosure Timeline

2010-11-09: Initial report sent to Microsoft
2010-11-09: Microsoft acknowledges and assigns the issues MSRC 10596, 10597, 10598
2010-12-13: Tenable asks Microsoft for an update
2011-01-05: Microsoft confirms the vulnerabilities exist
2011-06-02: Microsoft says a July or August timeframe is targeted
2011-08-02: Tenable asks Microsoft for an update
2011-08-02: Microsoft says an October release is targeted
2011-09-30: Microsoft assigns CVEs
2011-10-11: MS11-079 published along with related updates

All information within TRA advisories is provided “as is”, without warranty of any kind, including the implied warranties of merchantability and fitness for a particular purpose, and with no guarantee of completeness, accuracy, or timeliness. Individuals and organizations are responsible for assessing the impact of any actual or potential security vulnerability.

Tenable takes product security very seriously. If you believe you have found a vulnerability in one of our products, we ask that you please work with us to quickly resolve it in order to protect customers. Tenable believes in responding quickly to such reports, maintaining communication with researchers, and providing a solution in short order.

For more details on submitting vulnerability information, please see our Vulnerability Reporting Guidelines page.

If you have questions or corrections about this advisory, please email [email protected]