Hi,
DISCLAIMER:
In this article we may see an abnormal behaviors of weblogic. Which may not be necessarily a BUG but it is always to be aware of such behavior while using Weblogic. The idea behind making this page is just to make awareness among the WebLogic Admins to be alert specially when the some of these behaviors are related to WebLogic Security.
Some of the behaviors of WebLogic which may be due to inappropriate Security implementation in the Security system of WebLogic, Even if in some cases it is work as designed, Still it suggests to keep an eye on it and try to make those features more enhanced. Some of them are now fixed by the Application Server Vendor but still some need to be fixed or enhanced. The intentions here are not to point to the weak points of any Application Server but solely to make people aware about such strange or uncommon behaviors.
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Any WebServer or Application Server which runs on below mentioned JVM are not safe due to the security breach. For example if you just want to hang A server then just sent the following request to the Server using any HttpClient like JMeter or any other Utility which allows you to send the Http Header of your Choice.
Once you are able to send the following Http Request Header successfully to the Java based Application/Web Server …the Server will try to parse the Http Request Header and it will Hang while processing this request.
“GET”,”/”,headers={“Accept-Language”: “en-us;q=2.2250738585072012e-308”}
Just for an example try to run the following simple Java program which just tries to parse a Double value 2.2250738585072012e-308. As soon as you will run this program you will see that your JVM will Hang….and the CPU Utilization will be around 100% 😉
class HangJVM { public static void main(String[] args) { System.out.println("Test:"); double d = Double.parseDouble("2.2250738585072012e-308"); System.out.println("Value: " + d); } }
The JVMs which are affected are as following:
Java SE
JDK and JRE 6 Update 23 and earlier for Windows, Solaris, and Linux
JDK 5.0 Update 27 and earlier for Solaris 9
SDK 1.4.2_29 and earlier for Solaris 8
Java for Business
JDK and JRE 6 Update 23 and earlier for Windows, Solaris and Linux
JDK and JRE 5.0 Update 27 and earlier for Windows, Solaris and Linux
SDK and JRE 1.4.2_29 and earlier for Windows, Solaris and Linux
Save your JVM and your Application Server From Attack or Contact your Support 😉
Or Please get a Fix from Support Which Updates the “rt.jar” of the JVM The Fix Details are available in the following Link http://middlewaremagic.com/weblogic/?p=5393#comment-2821
And
Regarding the “Oracle Security Alert for CVE-2010-4476″You can get the Temp Security Patches related to this issue from the following link:http://www.oracle.com/technetwork/topics/security/alert-cve-2010-4476-305811.html
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Thanks
Jay SenSharma
February 9th, 2011 on 6:17 pm
Where did you get JDK 5.0 Update 27?
According to all Oracle sources Update 22 is the latest available, but maybe for Solaris they did some more…?
Thanks,
Werner
February 9th, 2011 on 6:29 pm
Hi Werner,
You need to contact Oracle Support for JDK5.0 Update27 as it is not mentioned in any of the Download Links. Regarding the “Oracle Security Alert for CVE-2010-4476” You can get the Temp Security Patches related to this issue from the following link: http://www.oracle.com/technetwork/topics/security/alert-cve-2010-4476-305811.html
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Keep Posting 🙂
Thanks
Jay SenSharma
February 10th, 2011 on 1:53 pm
Oracle has released a fix for security alert CVE-2010-4476 — the “Java Hangs on 2.2250738585072012e-308 bug.”
The fix comes in the form of something called the FPUpdater Tool, which updates rt.jar.
I tested it on my Windows XP system and it works.
Thx,
Unni
February 10th, 2011 on 10:36 pm
Hi Unni,
Thanks for sharing the useful info about the patch (FPUpdater Tool) and it’s functionality. 🙂
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Keep Sharing 🙂
Thanks
Jay SenSharma
February 10th, 2011 on 10:33 pm
More update is here http://www.infoq.com/news/2011/02/double_bug
February 11th, 2011 on 12:31 am
Hi Venu,
Thanks for sharing the Above link….It has really an in-depth description and remedy about this bug.
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Keep Sharing 😉
Thanks
Jay SenSharma