CVE-2014-2791 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 9 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Internet Explorer Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 02/08/2022
Microsoft Internet Explorer 9 suffered from a critical memory corruption vulnerability that enabled remote code execution and denial of service attacks through maliciously crafted web content. This vulnerability represented a significant security flaw in the browser's handling of memory management during web page rendering processes. The flaw occurred when Internet Explorer attempted to process specially crafted HTML elements or JavaScript code that triggered improper memory handling, leading to buffer overflows or other memory corruption conditions that could be exploited by attackers.
The technical implementation of this vulnerability involved Internet Explorer's rendering engine failing to properly validate memory allocations when processing certain web page elements. Attackers could construct malicious web pages containing specially formatted data structures that would cause the browser to allocate insufficient memory for processing operations, resulting in memory corruption that could be leveraged to execute arbitrary code with the privileges of the user running the browser. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though the specific implementation in this case involved heap memory corruption typical of modern browser exploits.
The operational impact of CVE-2014-2791 was severe given the widespread adoption of Internet Explorer 9 across enterprise environments and personal computing platforms. Attackers could exploit this vulnerability through drive-by downloads, malicious advertisements, or compromised websites that would automatically execute malicious code when users visited the compromised pages. The vulnerability was particularly dangerous because it required no user interaction beyond visiting a malicious website, making it an ideal candidate for automated exploitation campaigns. The memory corruption could also lead to denial of service conditions where the browser would crash or become unresponsive, effectively disrupting user productivity and system availability.
Security researchers identified that this vulnerability exploited weaknesses in the browser's memory management subsystem, particularly when handling complex HTML structures and JavaScript execution contexts. The flaw was classified under the ATT&CK technique T1203 - Exploitation for Client Execution, which specifically addresses the use of vulnerabilities to execute code on victim systems. Organizations running Internet Explorer 9 were particularly at risk since the vulnerability affected a widely used browser version that many enterprises had not yet migrated away from, creating a substantial attack surface. The exploitability of this vulnerability was further enhanced by the fact that it could be delivered through multiple vectors including email attachments, web-based attacks, and social engineering campaigns.
Mitigation strategies for CVE-2014-2791 primarily focused on immediate patching through Microsoft's security updates, as well as implementing browser hardening measures and network-based protections. Organizations should have deployed the Microsoft security bulletin MS14-021 which contained the necessary patches to address the memory corruption issues. Additional protective measures included implementing browser isolation techniques, disabling unnecessary browser features, and deploying web application firewalls to detect and block malicious content. The vulnerability also highlighted the importance of regular security updates and the need for organizations to maintain current patch management processes to protect against similar memory corruption vulnerabilities in other software components.