CVE-2016-3207 in Internet Explorer
Summary
by MITRE
The Microsoft (1) JScript 5.8 and (2) VBScript 5.7 and 5.8 engines, as used in Internet Explorer 9 through 11 and other products, allow 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-2016-3205 and CVE-2016-3206.
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Analysis
by VulDB Data Team • 08/24/2022
This vulnerability affects the scripting engines used in Microsoft Internet Explorer versions 9 through 11, specifically targeting the JScript 5.8 and VBScript 5.7 and 5.8 implementations. The flaw manifests as a memory corruption issue that can be exploited through maliciously crafted web content, allowing remote attackers to execute arbitrary code or induce denial of service conditions. The vulnerability represents a critical security gap in Microsoft's scripting engine architecture, where improper memory handling during script execution creates opportunities for attacker-controlled memory corruption that can be leveraged for privilege escalation and system compromise.
The technical implementation of this vulnerability stems from inadequate bounds checking and memory management within the scripting engines' interpretation and execution processes. When Internet Explorer processes malformed or malicious script code, the JScript and VBScript engines fail to properly validate memory allocations and deallocations, leading to buffer overflows or use-after-free conditions. This memory corruption occurs during the parsing and execution phases of script interpretation, where the engines do not adequately verify input parameters or maintain proper memory boundaries during dynamic code execution. The vulnerability is classified under CWE-125 as "Out-of-bounds Read" and CWE-787 as "Out-of-bounds Write," representing fundamental memory safety issues that have been historically prevalent in scripting engine implementations. The flaw specifically aligns with ATT&CK technique T1059.007 for "Scripting" and T1203 for "Exploitation for Client Execution, where adversaries leverage browser-based scripting vulnerabilities to execute malicious payloads.
The operational impact of this vulnerability extends beyond simple exploitation capabilities to encompass significant risks for enterprise environments and individual users. Attackers can craft web pages that, when visited by victims using affected Internet Explorer versions, automatically trigger the memory corruption conditions without user interaction. This makes the vulnerability particularly dangerous as it can be exploited through drive-by downloads or malicious websites that require no user input or interaction. The potential for privilege escalation exists when attackers leverage this vulnerability to execute code with the privileges of the current user context, potentially leading to full system compromise. Organizations running affected systems face heightened risk of data breaches, malware installation, and persistent backdoor access. The vulnerability's presence in Internet Explorer 9 through 11 creates a substantial attack surface given the widespread deployment of these browser versions across corporate and consumer environments.
Mitigation strategies for this vulnerability require immediate patch deployment through Microsoft's regular security updates, specifically addressing the scripting engine memory handling flaws. Organizations should implement browser hardening measures including disabling script execution in untrusted contexts, implementing content security policies, and restricting access to potentially malicious websites through network-level controls. Security teams should also consider deploying intrusion detection systems capable of identifying exploitation attempts targeting this specific vulnerability pattern. Additional protective measures include implementing sandboxing technologies, regularly updating browser versions to patched releases, and conducting thorough vulnerability assessments to identify systems running unsupported or unpatched Internet Explorer versions. Network administrators should consider implementing web application firewalls and browser isolation techniques to reduce exposure to such scripting engine vulnerabilities. The vulnerability's classification under Microsoft's security bulletin MS16-077 highlights the critical nature of prompt remediation efforts and the importance of maintaining current security patches across all affected platforms.