CVE-2012-4969
Microsoft Internet Explorer Use-After-Free Vulnerability
Description
CVE-2012-4969 is a use-after-free vulnerability in Microsoft Internet Explorer that allows remote attackers to execute arbitrary code via a crafted web site. The flaw occurs when Internet Explorer accesses a previously freed memory object during HTML rendering, enabling an attacker to control the contents of the freed memory and redirect program execution. CISA has included CVE-2012-4969 in its Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. With an EPSS score of 91.8% (99th percentile), this vulnerability represents a critical risk for any systems still running unpatched versions of Internet Explorer.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| microsoft | internet explorer | 6; 7; 8; 9 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- http://blog.vulnhunt.com/index.php/2012/09/17/ie-execcommand-fuction-use-after-free-vulnerability-0day_en/(Broken Link)
- http://dev.metasploit.com/redmine/projects/framework/repository/entry/modules/exploits/windows/browser/ie_execcommand_uaf.rb(Broken Link)
- http://eromang.zataz.com/2012/09/16/zero-day-season-is-really-not-over-yet/(Third Party Advisory)
- http://technet.microsoft.com/security/advisory/2757760(Patch, Vendor Advisory)
- http://www.kb.cert.org/vuls/id/480095(Third Party Advisory, US Government Resource)
- http://www.securitytracker.com/id?1027538(Third Party Advisory, VDB Entry)
- http://www.securityweek.com/new-internet-explorer-zero-day-being-exploited-wild(Third Party Advisory)
- http://www.us-cert.gov/cas/techalerts/TA12-255A.html(Third Party Advisory, US Government Resource)
- http://www.us-cert.gov/cas/techalerts/TA12-262A.html(Third Party Advisory, US Government Resource)
- http://www.us-cert.gov/cas/techalerts/TA12-265A.html(Third Party Advisory, US Government Resource)
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15729(Third Party Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2012-4969(US Government Resource)
Weakness Type
CWE-416: Use After Free
CVE-2012-4969 exploits a use-after-free condition in Microsoft Internet Explorer, where the browser continues to reference a memory object after it has been deallocated. When the freed memory is reallocated for a different purpose, the stale pointer dereference allows an attacker to manipulate the contents and achieve arbitrary code execution through controlled heap manipulation.
Learn more: CWE-416 — Use After Free
Impact Analysis
CVE-2012-4969 is remotely exploitable through a crafted web page — an attacker simply needs to lure a victim to a malicious website. No authentication or special privileges are required, and exploitation can occur without any additional user interaction beyond visiting the page. The use-after-free vulnerability enables arbitrary code execution with the privileges of the Internet Explorer process, which typically runs with the current user's permissions. This means confidentiality, integrity, and availability of the target system are fully at risk — an attacker can steal credentials, install malware, or establish persistent access. The EPSS score of 91.8% (99th percentile) indicates near-certain exploitation activity, making this one of the most actively exploited Internet Explorer vulnerabilities of its era.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2012-4969 in the wild by adding it to the Known Exploited Vulnerabilities catalog on June 8, 2022. The EPSS score of 91.8% places this vulnerability in the 99th percentile, indicating an extremely high probability of exploitation. This vulnerability was actively exploited in zero-day attacks before a patch was available, and it was a prominent target for exploit kits and drive-by download campaigns. While no specific ransomware association has been reported, the remote code execution capability via simple web page visits makes it highly effective for mass exploitation campaigns and watering hole attacks.
Remediation
- Apply Microsoft security updates immediately: Install all relevant security patches for Internet Explorer as directed by the CISA KEV required action to address the use-after-free vulnerability.
- Migrate away from Internet Explorer: Internet Explorer has reached end-of-life. Migrate all users and applications to a modern, supported browser such as Microsoft Edge, Google Chrome, or Mozilla Firefox.
- Implement Enhanced Protected Mode (EPM): If Internet Explorer must remain in use temporarily, enable Enhanced Protected Mode to run the browser in a more restricted sandbox that limits the impact of exploitation.
- Deploy web filtering and URL reputation services: Block access to known malicious domains and implement real-time URL reputation checking to prevent users from visiting sites hosting CVE-2012-4969 exploits.
- Monitor for exploitation indicators: Watch for unusual Internet Explorer process behavior including unexpected child process creation, shellcode execution patterns, or network connections to command-and-control infrastructure that may indicate successful exploitation.
Technical Details
CVE-2012-4969 is a use-after-free vulnerability in Microsoft Internet Explorer's HTML rendering engine. The vulnerability is triggered when Internet Explorer processes a crafted web page that causes a specific DOM object to be freed prematurely while a reference to it still exists. When the browser subsequently accesses the dangling pointer, it reads or writes to memory that may have been reallocated for a different object. By using heap spraying techniques to fill the freed memory with attacker-controlled data containing crafted function pointers or vtable entries, an attacker can redirect execution to arbitrary code. The vulnerability is classified under CWE-416, as the root cause is the continued use of a pointer after the memory it references has been deallocated. The reliable exploitability of this vulnerability through simple web page visits made it a prime target for exploit kit authors and advanced persistent threat actors.
Frequently Asked Questions
Is CVE-2012-4969 being actively exploited?
Yes. CISA has confirmed active exploitation of CVE-2012-4969 by adding it to the Known Exploited Vulnerabilities catalog. The EPSS score of 91.8% in the 99th percentile indicates near-certain exploitation, and this vulnerability was used in zero-day attacks before a patch was available.
What products are affected by CVE-2012-4969?
CVE-2012-4969 affects Microsoft Internet Explorer. Multiple versions of Internet Explorer were vulnerable, and the product has since reached end-of-life. All users should have migrated to a modern browser.
How do I fix CVE-2012-4969?
Apply all available Microsoft security updates for Internet Explorer. The most effective long-term remediation is to migrate entirely to a modern, supported browser such as Microsoft Edge, Google Chrome, or Mozilla Firefox, as Internet Explorer is end-of-life.
How severe is CVE-2012-4969?
CVE-2012-4969 is a critically severe vulnerability with an EPSS score in the 99th percentile. It enables remote code execution through a simple malicious web page visit, requiring no authentication. The use-after-free condition was actively exploited in zero-day attacks and remains dangerous on any system still running Internet Explorer.
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