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Windows Vulnerability in Animated Cursor Handling
MoreDruid writes "Secunia reports a vulnerability in Windows Animated Cursor Handling. According to the linked article, the rating is "extremely critical". Microsoft has put up their own advisory on the subject, confirming this is a vulnerability that affects Windows 2000, XP, 2003 and Vista. The exploit has already been used in the wild. From the Secunia page: The vulnerability is caused due to an unspecified error in the handling of animated cursors and can e.g. be exploited by tricking a user into visiting a malicious website using Internet Explorer or opening a malicious e-mail message. Successful exploitation allows execution of arbitrary code."
I guess you are not a student of Computer Science.
Every parameter from every possible input needs to be verified for its correctness. If there isn't you need a way of notifying the user or cleanly exiting the system to prevent cascading damage.
The concept is simple actual practice is hard.
A lot of the times these hacks are not found because they were looking for a way to hack the system but the realized there was a problem when they did something wrong but it didn't reutrn errors but had desasterious consequences.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
If you think you're not vulnerable because you won't be downloading an animated cursor, or you're not vulnerable because you have AV software, read this:
...which has a similar infection vector (by merely visiting a web page you get infected), and went undetected for 54 days.
http://www.secureworks.com/research/threats/gozi/
This latest silent exploit, which can be used by merely visiting a web page, will be used for other similar attacks.
Oolite: Elite-like game. For Mac, Linux and Windows
Who cares if it runs as root or not? It really doesn't make too much of a difference except on a multi-user system. I don't care about my OS installation--that is easy to do again. What I do care about is my data. Deleting or corrupting files in my user profile directory (C:\Documents and Settings\user\* or /home/user/* -- take your pick) is digital death for me (assuming a backup will not restore properly or new data hasn't been backed up yet).
It seems like every time someone comments about a security hole on Slashdot the response is along the lines of "Well, if this doesn't result in a root exploit, it isn't all that bad". If you agree with that statement, then go ahead and issue "rm -rf ~".
Computers input, store, manipulate, and output data. My data is important to me. Arbitrary code execution regardless of whether in my user context or a context with superuser privileges is a threat to that data.
For those people saying "turn off animated cursors" and such, I don't think that's a solution. IE allows a webpage (or email if you're using the IE rendering engine in Outlook) to replace your cursor using some IE-specific CSS code. It's as easy as changing the background for a webpage. Examples:
.ANI file which exploits the hole in IE.
body {cursor: url('cursor.ani');}
<BODY style="CURSOR: url('cursor.ani')">
<BODY style="CURSOR: url('http://www.example.com/cursor.ani')">
You can do it for the <BODY> element, or for other elements like <A>s. It then loads the specified
I am almost positive there is no way to disable this in IE.
Well, as another poster already said, it would be best if untrusted applications (like web browsers) were run as a different user from your main account. The only way it could access your data would be to require a password for privilege escalation. Unfortunately I don't know of any OS that does this. SELinux is neat, but I'm not sure it can do this without being overly restrictive.
Anyway, I think the bigger issue, though, is that root is bad. Not just for multi-user systems. The reason being because most malicious attacks are not aimed at running "rm -rf ~". They can, but that is not really in the interest of most of the people writing these exploits. They are interested in installing spyware, malware, and rootkits...all of which require root/administrator privileges. Other things too, like getting into the system logs and messing with memory owned by other processes, that help a cracker find and take advantage of exploits also require elevated privileges. So if your exploitable program simply runs as an unprivileged user you can get rid of a lot of these problems. It won't get rid of all problems, but it would help significantly.