CVE-2008-4844 in Internet Explorer
Summary
by MITRE
Use-after-free vulnerability in the CRecordInstance::TransferToDestination function in mshtml.dll in Microsoft Internet Explorer 5.01, 6, 6 SP1, and 7 allows remote attackers to execute arbitrary code via DSO bindings involving (1) an XML Island, (2) XML DSOs, or (3) Tabular Data Control (TDC) in a crafted HTML or XML document, as demonstrated by nested SPAN or MARQUEE elements, and exploited in the wild in December 2008.
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Analysis
by VulDB Data Team • 05/25/2025
The CVE-2008-4844 vulnerability represents a critical use-after-free condition within Microsoft Internet Explorer's mshtml.dll component that affects multiple versions including IE 5.01, 6, 6 SP1, and 7. This flaw occurs specifically within the CRecordInstance::TransferToDestination function, which handles data transfer operations for various XML data binding scenarios. The vulnerability manifests when Internet Explorer processes crafted HTML or XML documents containing DSO (Data Shape Objects) bindings, particularly involving XML Islands, XML DSOs, or Tabular Data Controls. The attack vector exploits the improper memory management during data transfer operations, creating a scenario where freed memory locations are accessed after the original memory has been reallocated, leading to potential code execution.
The technical implementation of this vulnerability involves the manipulation of nested HTML elements such as SPAN or MARQUEE tags that trigger the problematic code path within mshtml.dll. When these elements are processed, the CRecordInstance::TransferToDestination function encounters a race condition or improper memory deallocation sequence that results in a use-after-free condition. This memory corruption allows attackers to overwrite critical memory locations with malicious code, effectively enabling remote code execution. The vulnerability is particularly dangerous because it leverages legitimate XML data binding mechanisms that are commonly used in web applications, making it difficult to distinguish between benign and malicious content at runtime.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a sophisticated attack vector that was actively exploited in the wild during December 2008. The attack demonstrates the exploitation of legitimate browser functionality to achieve privilege escalation and system compromise. Security researchers have identified this vulnerability as mapping to CWE-416, which specifically addresses use-after-free conditions in memory management. The exploitability of this vulnerability aligns with ATT&CK technique T1059.007, which covers the use of scripting languages through Internet Explorer, and T1203, which involves exploitation of remote services through web browsers. The widespread nature of Internet Explorer usage at the time of exploitation meant that successful exploitation could result in complete system compromise, including credential theft, data exfiltration, and persistent backdoor installation.
Mitigation strategies for CVE-2008-4844 require immediate patching of affected Microsoft Internet Explorer versions through official security updates, as well as implementation of browser hardening measures. Organizations should consider disabling XML data binding features in Internet Explorer when not strictly required, implementing content security policies to limit script execution, and deploying application whitelisting solutions to prevent exploitation. Network-based protections such as web application firewalls can help detect and block malicious payloads, while endpoint detection and response solutions should monitor for unusual memory access patterns or process behavior that might indicate exploitation attempts. The vulnerability serves as a critical reminder of the importance of proper memory management in browser components and the necessity of regular security updates to protect against sophisticated zero-day exploits.