CVE-2011-1999 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 8 does not properly allocate and access memory, which allows remote attackers to execute arbitrary code via vectors involving a "dereferenced memory address," aka "Select Element Remote Code Execution Vulnerability."
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/07/2025
The vulnerability identified as CVE-2011-1999 represents a critical memory corruption flaw in Microsoft Internet Explorer 8 that enables remote code execution through improper memory management during HTML element processing. This vulnerability specifically affects the browser's handling of select elements within web pages, creating a scenario where attackers can manipulate memory addresses to execute malicious code on vulnerable systems. The flaw stems from inadequate bounds checking and memory allocation procedures when processing certain HTML constructs, particularly those involving dynamic element manipulation.
The technical mechanism behind this vulnerability involves a dereferenced memory address condition that occurs when Internet Explorer attempts to process select elements with specific characteristics. When a malicious web page contains crafted HTML code that triggers the browser's handling of these elements, the memory management routines fail to properly validate memory pointers before accessing them. This leads to a situation where attacker-controlled data can influence the memory access patterns, potentially allowing execution of arbitrary code with the privileges of the logged-in user. The vulnerability falls under CWE-125, which describes out-of-bounds read conditions, and specifically relates to improper memory access patterns that can be exploited through memory corruption attacks.
The operational impact of this vulnerability is severe as it allows remote attackers to execute malicious code on target systems without requiring any user interaction beyond visiting a compromised web page. Attackers can craft malicious websites that contain specially crafted HTML content designed to trigger the memory corruption condition in IE8's rendering engine. Once successfully exploited, the vulnerability provides attackers with full system compromise capabilities, potentially enabling them to install malware, steal sensitive data, or establish persistent access to affected systems. This makes the vulnerability particularly dangerous in enterprise environments where IE8 may be widely deployed and users may inadvertently visit compromised websites.
The exploitation of this vulnerability typically follows a pattern where attackers create web pages containing malicious HTML code that manipulates select elements in ways that trigger the memory corruption. The attack vector leverages the browser's HTML parsing and rendering engine to create conditions where memory addresses become corrupted or improperly referenced. Security researchers have documented that the vulnerability can be triggered through various methods including dynamic HTML manipulation, JavaScript injection, and malformed HTML structures that cause the browser to allocate memory incorrectly. Organizations should consider implementing multiple layers of defense including browser updates, network-based protections, and user education to mitigate the risk of exploitation.
Mitigation strategies for CVE-2011-1999 primarily focus on patch management and browser security hardening. Microsoft released security updates that addressed the memory allocation issues in IE8, and organizations should ensure all systems are updated with the latest security patches. Additionally, implementing browser security features such as Internet Explorer's Enhanced Security Configuration, disabling unnecessary browser features, and employing web application firewalls can provide additional protection. The vulnerability demonstrates the importance of proper memory management in web browsers and highlights the need for continuous security assessments of browser components. Organizations should also consider migrating away from unsupported browser versions to reduce exposure to such vulnerabilities. The ATT&CK framework categorizes this as a technique involving browser exploitation and memory corruption, emphasizing the need for defensive measures that address both the technical flaw and the exploitation patterns used by threat actors.