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How the mentioned CVE works (technical details):
CVE-2010-0249 is a use-after-free vulnerability in Internet Explorer’s handling of HTML objects. When IE renders a specially crafted web page, it creates and deletes certain objects (e.g., `HTML` elements, `CDATASection` nodes) in memory. Due to incorrect initialization and improper reference counting, a pointer to a deleted object is retained (dangling pointer). A remote attacker can then trigger a specific sequence of DOM manipulations—for example, using JavaScript to delete an object and later access its freed memory via a leftover reference. By controlling the content of the freed memory (e.g., with a heap spray technique), the attacker can redirect execution flow to shellcode. The vulnerability does not require user interaction beyond visiting a malicious website. Successful exploitation leads to arbitrary code execution in the context of the current user. Attackers leveraged this during Operation Aurora to target high-profile organizations. The flaw affects the way IE interacts with the `mshtml.dll` component, specifically in the memory management of `CButton` and similar layout objects. Exploitation often combines `onreadystatechange` or `onpropertychange` events to trigger the use-after-free. Microsoft acknowledged the attack in December 2009 and released an out-of-band advisory (979352) before a final patch.
dailycve form:
Platform: Internet Explorer
Version: 6,7,8
Vulnerability: Use-after-free RCE
Severity: Critical
date: 2009-12-25
Prediction: 2010-02-09
What Undercode Say:
Simulate heap spray check for CVE-2010-0249 echo "Checking IE memory patterns..." curl -s -H "User-Agent: Mozilla/4.0 (compatible; MSIE 7.0)" http://malicious-site/aurora.html | grep -i "spray" Log analysis for Aurora indicators grep -E "mshtml.dll|0x0a0a0a0a" /var/log/httpd/access.log | wc -l Metasploit auxiliary module detection msfconsole -q -x "use auxiliary/scanner/http/ie_aurora; set RHOSTS target; run; exit"
Exploit:
The exploit uses JavaScript to allocate a large block of memory (heap spray) with NOP sled and shellcode at predictable addresses (e.g., 0x0a0a0a0a). Then, it triggers the use-after-free by deleting a `CDATASection` node and accessing its properties via a retained pointer, causing IE to jump into the sprayed memory and execute arbitrary code.
Protection from this CVE:
- Apply Microsoft security bulletin MS10-002 (February 9, 2010) to patch the vulnerability.
- Enable DEP (Data Execution Prevention) and ASLR where possible.
- Disable Active Scripting in Internet Explorer’s Internet zone.
- Use EMET (Enhanced Mitigation Experience Toolkit) to block heap spray and ROP.
- Upgrade to a modern browser or Windows version with improved memory safety.
Impact:
Remote, unauthenticated attacker can execute arbitrary code with user privileges. Successful exploitation leads to complete system compromise, data theft, malware installation, and persistent access. During Operation Aurora, it was used in targeted attacks against Google, Adobe, and other tech firms to exfiltrate intellectual property and email archives.
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Sources:
Reported By: www.cve.org
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