CVE-2006-2382 in Internet Explorer
Summary
by MITRE
Heap-based buffer overflow in Microsoft Internet Explorer 5.01 SP4 and 6 SP1 and earlier allows remote attackers to execute arbitrary code via crafted UTF-8 encoded HTML that results in size discrepancies during conversion to Unicode, aka "HTML Decoding Memory Corruption Vulnerability."
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/22/2025
The CVE-2006-2382 vulnerability represents a critical heap-based buffer overflow affecting Microsoft Internet Explorer versions 5.01 Service Pack 4 and 6 Service Pack 1 and earlier. This vulnerability stems from improper handling of UTF-8 encoded HTML content during the conversion process to Unicode character representation. The flaw occurs when Internet Explorer encounters specially crafted HTML sequences that contain UTF-8 encoded characters, leading to miscalculations in memory allocation that result in buffer overflows within the heap memory region. This type of vulnerability falls under CWE-121 Heap-based Buffer Overflow, which is categorized as a memory corruption vulnerability that can be exploited to execute arbitrary code with the privileges of the user running the affected browser.
The technical exploitation of this vulnerability involves the manipulation of character encoding conversion routines within Internet Explorer's HTML parser. When processing UTF-8 encoded content, the browser's conversion logic fails to properly validate the size calculations required for converting multi-byte UTF-8 sequences into Unicode format. This discrepancy in size calculation causes the application to allocate insufficient memory for the converted Unicode string, leading to memory corruption when the overflow occurs. The vulnerability specifically targets the memory management functions responsible for handling character encoding transformations, making it particularly dangerous as it can be triggered through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious website.
The operational impact of CVE-2006-2382 is severe and far-reaching within enterprise and individual computing environments. Attackers can leverage this vulnerability to execute arbitrary code remotely, potentially gaining complete control over affected systems. The vulnerability's exploitation does not require user interaction beyond visiting a malicious webpage, making it particularly dangerous in phishing attacks and drive-by download scenarios. The heap-based nature of the overflow allows attackers to manipulate memory contents in ways that can bypass many traditional security measures, including address space layout randomization and data execution prevention mechanisms. This vulnerability has been classified under the MITRE ATT&CK framework as part of the T1203 - Exploitation for Client Execution technique, where adversaries leverage application vulnerabilities to execute malicious code on target systems.
Mitigation strategies for CVE-2006-2382 primarily involve immediate patching and system updates from Microsoft, as this vulnerability was addressed through security updates released in 2006. Organizations should implement comprehensive browser security policies that include disabling unnecessary browser features and implementing web content filtering solutions to prevent access to potentially malicious websites. Network-level protections such as intrusion detection systems and web proxies can help identify and block exploitation attempts targeting this vulnerability. Additionally, user education programs should emphasize the importance of avoiding untrusted websites and maintaining current security patches. The vulnerability's exploitation requires careful monitoring of browser memory usage patterns and implementation of runtime protection mechanisms that can detect anomalous memory allocation behaviors. Security professionals should also consider implementing application whitelisting policies that restrict execution of untrusted code, particularly in environments where legacy browser versions cannot be immediately updated due to compatibility concerns.