System Information Leak: Missing Catch Block - Revision history

KirstenS at 23:30, 7 April 2009

2009-04-07T23:30:37Z

KirstenS at 18:01, 10 February 2009

2009-02-10T18:01:48Z

KirstenS at 01:12, 6 November 2008

2008-11-06T01:12:02Z

KirstenS at 01:05, 1 October 2008

2008-10-01T01:05:03Z

Weilin Zhong: /* Examples */ formatting change

2006-07-21T16:44:54Z

‎Examples: formatting change

Weilin Zhong: Added contents provided by Fortify and Countermeasure discussion.

2006-07-21T16:44:00Z

Added contents provided by Fortify and Countermeasure discussion.

New page

{{Template:Vulnerability}}
{{Template:Fortify}}

==Abstract==

If a Servlet fails to catch all exceptions, it may reveal debugging information that will help an adversary form a plan of attack.

==Description==

When a Servlet throws an exception, the default error response the Servlet container sends back to the user typically includes debugging information. This information is of great value to an attacker. For example, a stack trace might show the attacker a malformed SQL query string, the type of database being used, and the version of the application container. This information enables the attacker to target known vulnerabilities in these components.

==Examples ==

'''Example 1'''

In the following method a DNS lookup failure will cause the Servlet to throw an exception.

protected void doPost (HttpServletRequest req,
HttpServletResponse res)
throws IOException {
String ip = req.getRemoteAddr();
InetAddress addr = InetAddress.getByName(ip);
...
out.println("hello " + addr.getHostName());
}

'''Example 2'''

The following method will throw a NullPointerException if the parameter "name" is not part of the request.

protected void doPost (HttpServletRequest req,
HttpServletResponse res)
throws IOException {
String name = getParameter("name");
...
out.println("hello " + name.trim());
}

==Related Threats==

==Related Attacks==

==Related Vulnerabilities==

==Related Countermeasures==

A good error handling mechanism always tries to capture all exceptions and returns a generic error message that does not reveal any details about the error and the application. Depending on the platform and container the application is running on, there can be different options.
* Set a generic custom error page for all unhandled exceptions at the container level. (Normally, this is set in the configuration file.) The generic custom error page should have a simple error message that does not reveal any details about the exception happened.
** In ASP.NET, it is the customError tag in the web.config file
* Use an global error handler to capture all unhandled exceptions.
** In ASP.NET, it is the Application_Error sub in the global.asax file.
* Handle the error in the page level
** In ASP.NET, it is the Page_Error sub on the aspx page or associated codebehind page

==Categories==

[[Category:Error Handling Vulnerability]]

[[Category:Java]]

[[Category:Implementation]]

[[Category:Code Snippet]]

[[Category:Servlet]]

← Older revision		Revision as of 23:30, 7 April 2009
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	#REDIRECT [[Information Leakage]]		#REDIRECT [[Information Leakage]]

−	~~__TOC__~~
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−	~~[[ASDR Table of Contents]]~~

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-{{Template:Vulnerability}}
+{{template:CandidateForDeletion}}
-{{Template:Fortify}}
+ #REDIRECT [[Information Leakage]]
 __TOC__
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 Last revision (mm/dd/yy): '''{{REVISIONMONTH}}/{{REVISIONDAY}}/{{REVISIONYEAR}}'''
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 TBD

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 {{Template:Fortify}}
-[[Category:FIXME|This is the text from the old template. This needs to be rewritten using the new template.]]
+__TOC__
 Last revision (mm/dd/yy): '''{{REVISIONMONTH}}/{{REVISIONDAY}}/{{REVISIONYEAR}}'''
-[[ASDR Table of Contents]]
+[[Category:FIXME|This is the text from the old template. This needs to be rewritten using the new template.]]
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 [[Category:Code Snippet]]
 [[Category:Servlet]]

@@ Line 2: / Line 2: @@
 {{Template:Fortify}}
-==Abstract==
+[[Category:FIXME|This is the text from the old template. This needs to be rewritten using the new template.]]
 ==Description==
 When a Servlet throws an exception, the default error response the Servlet container sends back to the user typically includes debugging information. This information is of great value to an attacker. For example, a stack trace might show the attacker a malformed SQL query string, the type of database being used, and the version of the application container. This information enables the attacker to target known vulnerabilities in these components.
-'''Example 1'''
 In the following method a DNS lookup failure will cause the Servlet to throw an exception.
@@ Line 27: / Line 42: @@
 </pre>
-'''Example 2'''
+===Example 2===
 The following method will throw a NullPointerException if the parameter "name" is not part of the request.
@@ Line 41: / Line 56: @@
 </pre>
-==Related Attacks==
+==Related [[Attacks]]==
-==Related Vulnerabilities==
+* [[Attack 1]]
-==Related Countermeasures==
 A good error handling mechanism always tries to capture all exceptions and returns a generic error message that does not reveal any details about the error and the application. Depending on the platform and container the application is running on, there can be different options.
@@ Line 57: / Line 81: @@
 ** In ASP.NET, it is the Page_Error sub on the aspx page or associated codebehind page
 [[Category:Error Handling Vulnerability]]
 [[Category:Java]]
 [[Category:Implementation]]
 [[Category:Code Snippet]]
 [[Category:Servlet]]

@@ Line 16: / Line 16: @@
 In the following method a DNS lookup failure will cause the Servlet to throw an exception.
 	protected void doPost (HttpServletRequest req,
 						HttpServletResponse res)
@@ Line 24: / Line 25: @@
 		out.println("hello " + addr.getHostName());
+	}
 '''Example 2'''
@@ Line 29: / Line 31: @@
 The following method will throw a NullPointerException if the parameter "name" is not part of the request.
 	protected void doPost (HttpServletRequest req,
 						HttpServletResponse res)
@@ Line 36: / Line 39: @@
 		out.println("hello " + name.trim());
+	}
 ==Related Threats==