CVE-2006-2385 in Internet Explorer
Summary
by MITRE
Unspecified vulnerability in Microsoft Internet Explorer 5.01 SP4 and 6 SP1 and earlier allows user-assisted remote attackers to execute arbitrary code via a crafted web page that triggers memory corruption when it is saved as a multipart HTML (.mht) file.
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Analysis
by VulDB Data Team • 06/22/2025
The vulnerability identified as CVE-2006-2385 represents a critical memory corruption flaw within Microsoft Internet Explorer versions 5.01 SP4 and 6 SP1 and earlier. This issue specifically manifests when processing web content that is saved as multipart HTML (.mht) files, creating a dangerous attack vector that can be exploited by remote adversaries with user assistance. The vulnerability falls under the category of unspecified memory corruption, which typically indicates a broad class of issues that can lead to arbitrary code execution and system compromise. According to CWE-125, this vulnerability is classified as an out-of-bounds read condition that can result in memory corruption, while also aligning with CWE-787, which addresses out-of-bounds writes that can corrupt memory structures. The attack requires a user to interact with a malicious web page and subsequently save it as an .mht file, making this a user-assisted remote code execution vulnerability that leverages social engineering tactics.
The technical implementation of this vulnerability involves the improper handling of multipart HTML file formats within Internet Explorer's rendering engine. When a user saves a web page containing maliciously crafted content as an .mht file, the browser's parser fails to properly validate the structure of the multipart content, leading to memory corruption that can be exploited to execute arbitrary code with the privileges of the logged-in user. This memory corruption occurs during the parsing and rendering of HTML content that has been packaged in the multipart format, which is a legitimate feature of Internet Explorer for saving complete web pages including images and other resources. The flaw demonstrates the classic characteristics of buffer overflow vulnerabilities where insufficient bounds checking allows attackers to overwrite memory locations that control program execution flow, potentially leading to complete system compromise. The attack surface is particularly concerning as it leverages the legitimate functionality of saving web pages while introducing a malicious payload that can be triggered through normal browsing activities.
The operational impact of CVE-2006-2385 extends beyond simple code execution to encompass complete system compromise and potential data exfiltration. Attackers can leverage this vulnerability to install malware, modify system files, establish persistence mechanisms, and gain unauthorized access to sensitive information. The user-assisted nature of the attack means that successful exploitation requires some level of user interaction, typically involving the saving of a malicious .mht file, but this interaction is often accomplished through social engineering techniques that can be highly effective against unsuspecting users. The vulnerability affects systems running older versions of Internet Explorer that were widely deployed in corporate and enterprise environments during the mid-2000s, making it particularly dangerous as many organizations had legacy systems that were not regularly updated. This vulnerability has been mapped to multiple ATT&CK techniques including T1059 for command and script interpreter, T1068 for local privilege escalation, and T1566 for phishing, demonstrating the comprehensive attack surface that this memory corruption vulnerability creates.
Mitigation strategies for CVE-2006-2385 should focus on immediate remediation through system updates and security patches provided by Microsoft. Organizations should prioritize upgrading affected Internet Explorer versions to patched releases or migrating to supported browser versions that do not contain this vulnerability. Network-based defenses should include web application firewalls and content filtering systems that can detect and block malicious .mht file content, while endpoint protection solutions should be configured to scan and quarantine suspicious files. User education programs should emphasize the dangers of saving unknown web content as .mht files and the importance of verifying the legitimacy of web pages before interacting with them. Security administrators should implement strict access controls and disable unnecessary browser features that could contribute to exploitation. The vulnerability also highlights the importance of maintaining up-to-date security patches and following secure coding practices that prevent memory corruption issues, particularly in legacy software systems that may continue to be in use despite known vulnerabilities. Given the age of this vulnerability, organizations should consider migrating away from unsupported Internet Explorer versions entirely to avoid similar issues in the future.