CVE-2008-4259 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 7 sometimes attempts to access uninitialized memory locations, which allows remote attackers to execute arbitrary code via a crafted HTML document that triggers memory corruption, related to a WebDAV request for a file with a long name, aka "HTML Objects Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 05/25/2025
The vulnerability identified as CVE-2008-4259 represents a critical memory corruption flaw in Microsoft Internet Explorer 7 that stems from improper handling of WebDAV requests involving excessively long filenames. This issue manifests when the browser processes HTML documents containing crafted WebDAV operations that reference files with unusually long names, leading to the exploitation of uninitialized memory locations. The flaw exists within the browser's memory management mechanisms where it fails to properly validate or initialize memory regions before accessing them during WebDAV file operations. This vulnerability falls under the CWE-457 category of "Use of Uninitialized Variable" and specifically relates to memory corruption vulnerabilities that enable arbitrary code execution. The attack vector requires a remote attacker to craft a malicious HTML document that, when loaded by an affected IE7 browser, triggers the memory corruption through a WebDAV request mechanism.
The technical exploitation of this vulnerability occurs when Internet Explorer processes a WebDAV request for a file with an excessively long name, causing the browser to attempt access to memory locations that have not been properly initialized. The uninitialized memory access creates a predictable pattern that attackers can leverage to execute arbitrary code with the privileges of the user running the browser. The flaw is particularly dangerous because it can be triggered through web-based attacks without requiring any special privileges or user interaction beyond visiting a malicious website. This type of vulnerability is classified under the ATT&CK technique T1203 "Exploitation for Client Execution" and represents a classic example of heap-based memory corruption that allows privilege escalation. The memory corruption results from the browser's failure to properly validate the length of filenames in WebDAV requests, causing it to allocate memory without proper initialization before accessing those memory regions.
The operational impact of CVE-2008-4259 is severe and far-reaching, as it enables remote code execution in the context of the logged-on user, potentially allowing attackers to install malware, steal sensitive information, or establish persistent access to compromised systems. This vulnerability affects organizations using Internet Explorer 7 in enterprise environments, particularly those with WebDAV-enabled servers or applications that might trigger the problematic code path. The exploitability of this vulnerability is relatively high since it can be delivered through standard web traffic and does not require any user interaction beyond visiting a malicious website. Organizations running IE7 on systems that access WebDAV resources are particularly vulnerable, as the attack surface expands to include any environment where WebDAV operations might be performed. The vulnerability can be exploited through various attack vectors including phishing emails, compromised websites, or malicious advertisements that deliver the crafted HTML payload.
Mitigation strategies for CVE-2008-4259 primarily involve immediate patching of affected systems through Microsoft security updates, as the vulnerability was addressed in Microsoft's regular security bulletins for that period. Organizations should implement network-based protections including web application firewalls and content filtering solutions that can detect and block malicious WebDAV requests. Browser isolation techniques and sandboxing can provide additional protection layers, while disabling WebDAV functionality where possible reduces the attack surface. Security monitoring should focus on detecting unusual WebDAV traffic patterns and attempts to access files with abnormally long names. The vulnerability also highlights the importance of keeping browsers updated and implementing proper security configurations. Organizations should consider transitioning away from Internet Explorer 7 to more modern browser versions that have better memory management and security features. Regular security assessments and vulnerability scanning should include checks for this specific memory corruption pattern, and incident response procedures should be updated to address potential exploitation of this vulnerability through remote code execution.