CVE-2017-8519 in Internet Explorer
Summary
by MITRE
Internet Explorer in Microsoft Windows 7 SP1, Windows Server 2008 and R2 SP1, Windows 8.1 and Windows RT 8.1, and Windows Server 2012 and R2 allow an attacker to execute arbitrary code in the context of the current user when Internet Explorer improperly accesses objects in memory, aka "Internet Explorer Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8547.
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Analysis
by VulDB Data Team • 12/28/2020
The vulnerability described in CVE-2017-8519 represents a critical memory corruption flaw within Microsoft Internet Explorer that affects multiple Windows operating system versions including Windows 7 SP1, Windows Server 2008 and R2 SP1, Windows 8.1, Windows RT 8.1, and Windows Server 2012 and R2. This vulnerability specifically exploits how Internet Explorer handles object memory management, creating an opportunity for attackers to execute arbitrary code with the privileges of the currently logged-in user. The flaw stems from improper memory access patterns that occur when Internet Explorer processes certain web content, making it particularly dangerous in targeted attack scenarios.
From a technical perspective, this memory corruption vulnerability falls under the CWE-125 vulnerability category, which describes "Out-of-bounds Read" conditions where software attempts to read memory locations beyond the intended boundaries of allocated memory regions. The vulnerability manifests when Internet Explorer encounters maliciously crafted web content that triggers improper object handling in memory, potentially leading to buffer overflows or other memory corruption conditions. Attackers can leverage this flaw by crafting malicious web pages or documents that, when viewed in Internet Explorer, cause the browser to access invalid memory locations and subsequently execute malicious code. The vulnerability operates at the user privilege level, meaning successful exploitation would allow attackers to perform actions that the current user can perform, including file operations, registry modifications, and potentially privilege escalation depending on the user's permissions.
The operational impact of CVE-2017-8519 extends beyond simple remote code execution as it represents a significant threat vector for advanced persistent threat campaigns and targeted attacks. Security researchers have noted that this vulnerability is particularly concerning because it can be exploited through various attack vectors including malicious websites, email attachments, and compromised web services. The vulnerability's exploitation typically requires user interaction, such as visiting a malicious website or opening a specially crafted document, but once triggered, it provides attackers with persistent access to the compromised system. This makes it particularly attractive for threat actors who seek to establish long-term presence on target networks, as the vulnerability can be used to deploy additional malware, establish backdoors, or facilitate further reconnaissance activities.
Mitigation strategies for CVE-2017-8519 should encompass multiple layers of defense including immediate patch deployment, browser hardening, and network-based protections. Microsoft released security updates for this vulnerability as part of their regular patching cycle, and organizations should prioritize applying these patches to all affected systems. Additionally, implementing browser isolation techniques, disabling unnecessary browser features, and employing sandboxing technologies can significantly reduce the attack surface. Network security controls such as web application firewalls, content filtering, and intrusion detection systems can help identify and block malicious traffic targeting this vulnerability. Organizations should also consider implementing user education programs to reduce the likelihood of successful exploitation through social engineering attacks that rely on user interaction with malicious content. The ATT&CK framework categorizes this vulnerability under the T1059.001 technique for Command and Scripting Interpreter, as exploitation typically involves executing malicious code through the compromised browser environment, making comprehensive endpoint protection essential for defending against such threats.