CVE-2016-3389 in Edge
Summary
by MITRE
The Chakra JavaScript engine in Microsoft Edge allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Scripting Engine Memory Corruption Vulnerability," a different vulnerability than CVE-2016-3386, CVE-2016-7190, and CVE-2016-7194.
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Analysis
by VulDB Data Team • 09/23/2022
The vulnerability identified as CVE-2016-3389 represents a critical memory corruption flaw within Microsoft Edge's Chakra JavaScript engine, which serves as the core component responsible for executing JavaScript code in the browser environment. This vulnerability specifically affects the scripting engine's handling of memory management during JavaScript execution, creating a pathway for malicious actors to exploit memory corruption issues that can lead to arbitrary code execution or system-wide denial of service conditions. The Chakra engine, designed to optimize JavaScript performance through Just-In-Time compilation and advanced memory management techniques, contains a flaw that allows attackers to manipulate memory structures in ways that were not properly accounted for during the engine's development lifecycle.
The technical nature of this vulnerability stems from improper memory handling within the Chakra engine's JavaScript interpretation and execution processes. Attackers can craft malicious web pages containing specially designed JavaScript code that, when executed by Edge's browser engine, triggers memory corruption conditions. These conditions typically manifest through buffer overflows, use-after-free errors, or other memory management flaws that occur when the engine attempts to allocate, access, or deallocate memory regions during script execution. The vulnerability operates at a low level within the browser's architecture, making it particularly dangerous as it can bypass many traditional security mechanisms and directly impact the browser's core operational memory space. According to CWE classification, this vulnerability maps to CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, both of which are common manifestations of memory corruption vulnerabilities in scripting engines.
The operational impact of CVE-2016-3389 extends beyond simple browser compromise, as successful exploitation can result in complete system takeover or service disruption for affected users. When an attacker successfully triggers this vulnerability, they can execute arbitrary code with the privileges of the Edge browser process, potentially leading to privilege escalation attacks that allow access to sensitive user data, system files, or network resources. The memory corruption can also cause the browser to crash or become unresponsive, creating denial of service conditions that prevent legitimate users from accessing web content. This vulnerability is particularly concerning in enterprise environments where Microsoft Edge is widely deployed, as it can serve as a vector for advanced persistent threats or mass exploitation campaigns targeting multiple systems simultaneously. The vulnerability's similarity to other related CVEs such as CVE-2016-3386, CVE-2016-7190, and CVE-2016-7194 demonstrates a pattern of memory corruption issues within the Chakra engine that required coordinated remediation efforts across multiple security patches.
Mitigation strategies for CVE-2016-3389 primarily involve immediate patch deployment through Microsoft's regular security updates, as well as implementing browser security controls such as Enhanced Protected Mode and Site Isolation features that limit the impact of potential exploitation attempts. Organizations should prioritize patch management processes to ensure all Edge installations receive the necessary security updates promptly. Browser hardening techniques including disabling unnecessary JavaScript features, implementing content security policies, and using sandboxing mechanisms can provide additional layers of protection against exploitation attempts. From an ATT&CK framework perspective, this vulnerability would be classified under techniques related to exploitation of known vulnerabilities and privilege escalation, with defenders needing to monitor for indicators of compromise related to unusual JavaScript execution patterns or memory access anomalies. Network-based protections such as web application firewalls and intrusion detection systems can help detect and block malicious web content designed to exploit this vulnerability, though the most effective mitigation remains timely patch deployment and proper security configuration management.