CVE-2017-8649 in Edge
Summary
by MITRE
Microsoft Edge in Microsoft Windows 10 1607, 1703, and Windows Server 2016 allows an attacker to execute arbitrary code in the context of the current user, due to the way that Microsoft browser JavaScript engines render content when handling objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8660, CVE-2017-8729, CVE-2017-8738, CVE-2017-8740, CVE-2017-8741, CVE-2017-8748, CVE-2017-8752, CVE-2017-8753, CVE-2017-8755, CVE-2017-8756, and CVE-2017-11764.
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Analysis
by VulDB Data Team • 01/11/2021
The vulnerability identified as CVE-2017-8649 represents a critical memory corruption flaw within Microsoft Edge's JavaScript engine, specifically affecting Windows 10 versions 1607 and 1703 along with Windows Server 2016. This vulnerability falls under the broader category of scripting engine vulnerabilities, which are particularly dangerous because they can be exploited to execute arbitrary code with the privileges of the current user. The flaw manifests when the browser's JavaScript rendering engines process objects in memory, creating conditions where attackers can manipulate memory structures to achieve unauthorized code execution. This type of vulnerability is classified as a memory corruption issue that aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations. The vulnerability operates at the intersection of browser security and operating system protection mechanisms, making it a prime target for sophisticated attack vectors that leverage the trust users place in their web browsers.
The technical exploitation of CVE-2017-8649 occurs through a carefully crafted malicious webpage that triggers the memory corruption bug during JavaScript execution. When Microsoft Edge processes malformed or specially constructed JavaScript code, the browser's memory management routines fail to properly validate object boundaries, allowing attackers to overwrite memory locations with malicious code. This memory corruption can be leveraged to bypass modern security mitigations such as address space layout randomization and data execution prevention, as the attacker operates within the same process context as the legitimate browser. The vulnerability's exploitation typically follows a pattern where attackers first deliver a payload through a compromised website or phishing email, then execute a memory corruption attack that can lead to full system compromise. The ATT&CK framework categorizes this as a code injection technique under the T1059.007 sub-technique, specifically targeting the scripting engine component of web browsers. The vulnerability's impact extends beyond simple code execution to potentially allow privilege escalation, as attackers can manipulate the browser's memory to gain elevated system access.
The operational impact of CVE-2017-8649 is significant given that Microsoft Edge was the default browser on Windows 10 systems and was frequently used for web browsing activities. The vulnerability could be exploited through various attack vectors including malicious websites, email attachments, or compromised web services that deliver the malicious JavaScript payload. Once successfully exploited, the vulnerability provides attackers with the ability to execute arbitrary code in the context of the current user, potentially leading to complete system compromise if the user has administrative privileges. The attack surface is particularly broad as it affects multiple versions of Windows 10 and Windows Server 2016, making it a widespread concern for organizations. The vulnerability's exploitation can result in data theft, system monitoring, lateral movement within networks, and establishment of persistent backdoors. Organizations running affected systems were vulnerable to sophisticated attacks that could bypass traditional security controls, as the exploitation occurs within the trusted browser environment where security boundaries are typically relaxed. This makes the vulnerability particularly dangerous in enterprise environments where users may have elevated privileges and access to sensitive systems.
Mitigation strategies for CVE-2017-8649 focus on both immediate patching and operational security measures. Microsoft released security updates that addressed the memory corruption issue by fixing the JavaScript engine's object handling routines and improving memory validation checks. Organizations should prioritize immediate deployment of the relevant security patches, as the vulnerability was actively exploited in the wild during its disclosure period. Additional mitigations include implementing browser hardening measures such as disabling JavaScript in untrusted environments, using application whitelisting policies, and employing sandboxing techniques to isolate browser processes. Network-level protections such as web application firewalls and content filtering can help prevent access to known malicious sites that might exploit this vulnerability. Security monitoring should include detection of unusual JavaScript execution patterns and memory access anomalies that could indicate exploitation attempts. The vulnerability also highlights the importance of keeping all software components up to date, as the memory corruption occurred within the browser's core rendering engine. Organizations should also consider implementing user education programs to reduce the risk of social engineering attacks that deliver malicious payloads through phishing campaigns or compromised websites. The ATT&CK framework suggests implementing defensive measures such as process isolation, code integrity checks, and monitoring for suspicious memory modification patterns to detect potential exploitation attempts.