CVE-2017-11838 in Edge
Summary
by MITRE
ChakraCore and Internet Explorer in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8.1 and Windows RT 8.1, Windows Server 2012 R2, and Microsoft Edge and Internet Explorer in Windows 10 Gold, 1511, 1607, 1703, 1709, Windows Server 2016 and Windows Server, version 1709 allows an attacker to gain the same user rights as the current user, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-11836, CVE-2017-11837, CVE-2017-11839, CVE-2017-11840, CVE-2017-11841, CVE-2017-11843, CVE-2017-11846, CVE-2017-11858, CVE-2017-11859, CVE-2017-11861, CVE-2017-11862, CVE-2017-11866, CVE-2017-11869, CVE-2017-11870, CVE-2017-11871, and CVE-2017-11873.
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Analysis
by VulDB Data Team • 01/23/2021
The vulnerability identified as CVE-2017-11838 represents a critical memory corruption flaw within Microsoft's ChakraCore JavaScript engine and Internet Explorer components across multiple Windows operating systems. This vulnerability specifically affects Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8.1, Windows RT 8.1, Windows Server 2012 R2, and various Windows 10 versions including 1511, 1607, 1703, and 1709, along with Windows Server 2016 and Server version 1709. The flaw manifests in how the scripting engine manages objects in memory, creating a pathway for malicious actors to execute arbitrary code with the privileges of the currently logged-in user. This represents a significant security risk as it allows for privilege escalation without requiring administrative credentials, making it particularly dangerous in enterprise environments where users often operate with standard user privileges. The vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions in memory management, and aligns with ATT&CK technique T1068 which covers local privilege escalation through exploitation of software vulnerabilities.
The technical exploitation of this vulnerability occurs when the ChakraCore engine processes certain JavaScript objects in memory, leading to improper memory handling that can be manipulated by attackers to execute malicious code. The memory corruption aspect means that an attacker can potentially overwrite memory locations with controlled data, allowing them to redirect program execution flow or inject malicious payloads. This type of vulnerability typically arises from insufficient bounds checking or improper memory allocation handling within the JavaScript engine's memory management subsystem. The impact is particularly severe because the vulnerability can be triggered through web-based attacks, making it accessible to threat actors who can deliver malicious content through compromised websites, email attachments, or other vector that loads JavaScript code into the vulnerable browsers or applications. The exploitability of this vulnerability is enhanced by the fact that it affects widely deployed components, making it a prime target for automated exploitation campaigns.
The operational impact of CVE-2017-11838 extends beyond simple code execution, as successful exploitation results in full user-level privilege escalation. This means that if an attacker can successfully compromise a user's session through this vulnerability, they gain complete control over that user's account, including access to all files, applications, and network resources accessible to that user. In enterprise environments, this could lead to lateral movement within networks, data exfiltration, and the establishment of persistent backdoors. The vulnerability's presence across multiple Windows versions and browsers creates a wide attack surface, making it particularly attractive to threat actors who seek to maximize their exploitation potential. Organizations running affected systems face significant risk of unauthorized access, data breaches, and potential system compromise, especially when users interact with untrusted web content or receive malicious email attachments. The vulnerability's classification as a memory corruption issue also means that exploitation may be relatively stable and reliable, increasing the likelihood of successful attacks in real-world scenarios.
Mitigation strategies for CVE-2017-11838 should focus on immediate patch deployment through Microsoft's security updates, which address the underlying memory handling issues in the ChakraCore engine. Organizations should prioritize patching all affected Windows systems, particularly those running older versions of Windows 7, 8.1, and the various Windows 10 releases mentioned in the vulnerability description. Network segmentation and browser hardening measures can provide additional protection layers, including disabling JavaScript in trusted environments where possible and implementing strict web content filtering. Security monitoring should be enhanced to detect potential exploitation attempts through unusual memory access patterns or suspicious process behavior. Additionally, organizations should consider implementing exploit prevention technologies such as application whitelisting, exploit protection features, and advanced threat detection solutions that can identify and block exploitation attempts targeting this specific vulnerability. The ATT&CK framework's T1068 technique emphasizes the importance of monitoring for privilege escalation activities, making it crucial for security teams to implement comprehensive monitoring for suspicious user behavior that might indicate successful exploitation of this vulnerability.