CVE-2011-0346 in Internet Explorer
Summary
by MITRE
Use-after-free vulnerability in the ReleaseInterface function in MSHTML.DLL in Microsoft Internet Explorer 6, 7, and 8 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via vectors related to the DOM implementation and the BreakAASpecial and BreakCircularMemoryReferences functions, as demonstrated by cross_fuzz, aka "MSHTML Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 01/26/2025
The CVE-2011-0346 vulnerability represents a critical use-after-free condition within Microsoft Internet Explorer's MSHTML.DLL component, affecting versions 6, 7, and 8. This flaw resides in the ReleaseInterface function and manifests through memory corruption issues that arise during DOM (Document Object Model) processing. The vulnerability specifically exploits the interaction between BreakAASpecial and BreakCircularMemoryReferences functions, creating a scenario where freed memory locations are accessed after being deallocated, leading to unpredictable behavior and potential code execution.
This memory corruption vulnerability operates through a sophisticated exploitation chain that leverages the browser's document object model handling capabilities. When Internet Explorer processes certain web content, particularly in scenarios involving complex DOM manipulations and memory management operations, the ReleaseInterface function fails to properly manage reference counts for COM objects. The BreakAASpecial and BreakCircularMemoryReferences functions, which are designed to handle special cases in memory cleanup, create conditions where objects are prematurely freed while still being referenced elsewhere in the application's memory space. This creates a use-after-free condition that attackers can manipulate to execute arbitrary code or cause application crashes.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to include full remote code execution capabilities. Attackers can craft malicious web pages that, when loaded in affected Internet Explorer versions, trigger the memory corruption condition and subsequently execute malicious payloads with the privileges of the user running the browser. The vulnerability's exploitation requires careful crafting of web content that can trigger the specific memory management paths, making it particularly dangerous in targeted attacks. The cross_fuzz demonstration proved that this vulnerability could be reliably triggered through various web page construction techniques, making it a significant threat to users of these older browser versions.
Security researchers have classified this vulnerability according to CWE-416, which describes the use of freed memory condition, and it aligns with ATT&CK technique T1203, involving legitimate credentials and privilege escalation through memory corruption exploits. The vulnerability's presence in multiple IE versions demonstrates how memory management flaws can persist across product iterations, highlighting the importance of comprehensive security testing and timely patch deployment. Organizations using these affected browser versions face elevated risk of compromise, as the vulnerability can be exploited without user interaction in many scenarios, making it particularly dangerous in enterprise environments where legacy browser support is maintained. The recommended mitigation strategy involves immediate patch deployment through Microsoft's security updates, browser version upgrades to supported releases, and implementation of additional security controls such as browser sandboxing and network-based protections to reduce the attack surface and limit potential exploitation success rates.