CVE-2016-7242 in Edge
Summary
by MITRE
The Chakra JavaScript scripting 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-2016-7200, CVE-2016-7201, CVE-2016-7202, CVE-2016-7203, CVE-2016-7208, CVE-2016-7240, and CVE-2016-7243.
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Analysis
by VulDB Data Team • 09/29/2022
The CVE-2016-7242 vulnerability represents a critical memory corruption flaw within Microsoft Edge's Chakra JavaScript engine that enables remote code execution or denial of service attacks through malicious web content. This vulnerability specifically affects the scripting engine's handling of JavaScript objects and memory management operations, creating a pathway for attackers to manipulate memory structures and execute arbitrary code on affected systems. The flaw resides in how the Chakra engine processes certain JavaScript constructs, particularly those involving object manipulation and memory allocation that can lead to heap corruption or stack overflow conditions. Security researchers identified this vulnerability as distinct from several other related issues affecting the same engine, emphasizing its unique exploitation vectors and attack surface.
The technical implementation of this vulnerability involves the Chakra JavaScript engine's improper handling of JavaScript objects during memory allocation and deallocation processes. When processing specially crafted JavaScript code, the engine fails to properly validate object references and memory boundaries, leading to memory corruption that can be exploited to overwrite critical memory locations. Attackers can leverage this flaw by hosting malicious JavaScript code on a compromised website that, when executed in Microsoft Edge, triggers the memory corruption conditions. The vulnerability typically manifests through specific patterns in JavaScript object creation, method invocation, or property access that cause the engine to improperly manage memory resources, ultimately allowing attackers to gain control over the execution flow of the browser process.
From an operational impact perspective, this vulnerability presents significant risks to enterprise environments where Microsoft Edge is the primary browser or where users regularly access untrusted web content. The remote code execution capability means that attackers can potentially install malware, establish persistence mechanisms, or escalate privileges without requiring local system access. The denial of service aspect can be equally damaging, as it can cause browser crashes or system instability that disrupts business operations and user productivity. Organizations running Microsoft Edge in production environments face potential exposure to sophisticated attacks that could compromise sensitive data or infrastructure, particularly when users browse the internet or access web applications that might contain malicious JavaScript payloads.
Mitigation strategies for CVE-2016-7242 should include immediate deployment of Microsoft's security patches and updates to ensure the Chakra engine receives proper memory management fixes. Organizations should also implement browser hardening measures such as disabling unnecessary JavaScript features, implementing content security policies, and using sandboxing technologies to limit the impact of potential exploitation. Network-level defenses including web application firewalls and intrusion detection systems can help identify and block malicious JavaScript traffic. Additionally, security teams should conduct regular vulnerability assessments targeting Microsoft Edge installations and implement user education programs to reduce the risk of visiting compromised websites. The vulnerability aligns with CWE-125, which addresses out-of-bounds read conditions, and potentially CWE-787, concerning out-of-bounds write operations, while mapping to ATT&CK techniques involving exploitation of software vulnerabilities and privilege escalation through browser-based attacks. Organizations should also consider implementing browser isolation technologies and maintaining up-to-date threat intelligence feeds to proactively identify and respond to exploitation attempts targeting this and similar vulnerabilities in web browsers.