CVE-2014-0307 in Internet Explorer
Summary
by MITRE
Use-after-free vulnerability in Microsoft Internet Explorer 9 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a certain sequence of manipulations of a TextRange element, aka "Internet Explorer Memory Corruption Vulnerability."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/07/2026
The CVE-2014-0307 vulnerability represents a critical use-after-free flaw in Microsoft Internet Explorer 9 that enables remote code execution and denial of service conditions through improper memory management. This vulnerability specifically targets the TextRange element manipulation within the browser's rendering engine, creating a scenario where freed memory blocks are accessed after being deallocated. The flaw occurs when Internet Explorer processes certain sequences of operations involving text selection and manipulation, leading to memory corruption that attackers can exploit to gain control over the affected system. The vulnerability's impact extends beyond simple memory corruption as it provides attackers with a pathway to execute arbitrary code within the context of the user's session, potentially leading to full system compromise.
The technical implementation of this vulnerability stems from improper handling of reference counting and memory deallocation within Internet Explorer's TextRange object management system. When a TextRange element undergoes specific manipulation sequences, the browser's garbage collector may prematurely release memory associated with the object while other code paths still reference it. This creates a use-after-free condition where subsequent operations on the freed memory block can trigger unpredictable behavior including code execution. The vulnerability manifests through a complex interaction between JavaScript engine components and the browser's document object model, specifically involving the Range and TextRange interfaces that handle text selection and manipulation operations.
From an operational perspective, this vulnerability presents significant risk to enterprise environments as it allows attackers to remotely compromise systems without requiring user interaction beyond visiting a malicious webpage. The exploit requires minimal user engagement and can be delivered through various attack vectors including phishing emails, compromised websites, or malicious advertisements. Once successfully exploited, the vulnerability enables attackers to execute malicious code with the privileges of the logged-in user, potentially leading to complete system takeover. The memory corruption aspect makes detection particularly challenging as the behavior can appear random or inconsistent, complicating both exploitation and defensive measures.
Security professionals should implement multiple layers of defense to protect against CVE-2014-0307 exploitation. The primary mitigation involves applying Microsoft's security patches promptly, as the vulnerability was addressed through proper memory management fixes in subsequent updates. Organizations should also deploy enhanced browser security configurations including Internet Explorer's built-in protections such as Address Space Layout Randomization and Data Execution Prevention. Network-based protections including web application firewalls and content filtering systems can help detect and block malicious content targeting this vulnerability. Additionally, user education programs should emphasize the importance of avoiding untrusted websites and maintaining updated software versions. This vulnerability aligns with CWE-416 which specifically addresses use-after-free conditions, and represents a typical example of techniques used in the attack pattern category described in MITRE ATT&CK framework under T1203 for Exploitation for Execution. The remediation approach should include both immediate patch deployment and long-term browser security hardening strategies to prevent similar vulnerabilities from being exploited in the future.