CVE-2016-0187 in Windows
Summary
by MITRE
The Microsoft (1) JScript 5.8 and (2) VBScript 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-2016-0189.
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Analysis
by VulDB Data Team • 08/18/2022
The vulnerability identified as CVE-2016-0187 represents a critical memory corruption flaw within the scripting engines of Microsoft Internet Explorer versions 9 through 11. This vulnerability affects both JScript 5.8 and VBScript 5.8 engines, which are integral components of the browser's client-side scripting capabilities. The flaw enables remote attackers to execute arbitrary code or induce denial of service conditions through the exploitation of crafted web content, making it a significant threat to web browser security. The vulnerability is categorized under CWE-125 as an out-of-bounds read condition, which occurs when the scripting engines fail to properly validate memory access during script execution.
The technical implementation of this vulnerability stems from improper memory management within the scripting engine's object model handling. When Internet Explorer processes maliciously crafted web pages containing specially constructed JavaScript or VBScript code, the engines fail to perform adequate bounds checking on memory allocations. This allows attackers to manipulate memory pointers and overwrite critical system resources, potentially leading to arbitrary code execution with the privileges of the current user. The vulnerability manifests as heap corruption during script parsing and execution phases, where the engines allocate insufficient memory for object representations or fail to properly handle memory deallocation sequences.
From an operational perspective, this vulnerability presents a severe risk to enterprise environments where Internet Explorer remains in use, particularly in legacy systems that have not been migrated to modern browsers. Attackers can leverage this vulnerability through drive-by download scenarios where users visit compromised websites or receive malicious email attachments containing crafted web content. The exploitation typically requires user interaction, such as visiting a malicious website, but once triggered, the vulnerability can lead to complete system compromise. The impact extends beyond individual user sessions to potentially affect entire corporate networks through lateral movement and privilege escalation attacks.
The attack surface for this vulnerability aligns with the MITRE ATT&CK framework under the Tactic of Execution and Defense Evasion. Specifically, the vulnerability maps to techniques involving command and script execution through web browsers, as well as process injection methods that exploit memory corruption to gain unauthorized access. Security professionals should note that this vulnerability is distinct from CVE-2016-0189, which addresses a different memory corruption issue within the same scripting engines, highlighting the complexity of Microsoft's scripting engine security landscape during this period. Organizations should implement immediate mitigations including browser updates, security patches, and network-based protections such as browser isolation solutions to prevent exploitation attempts.
Mitigation strategies for CVE-2016-0187 should include immediate deployment of Microsoft security updates and patches, particularly the cumulative security updates released in January 2016. Network administrators should consider implementing additional security layers such as enhanced browser security policies, sandboxing mechanisms, and web application firewalls to reduce the attack surface. The vulnerability demonstrates the importance of keeping browser components updated, as the scripting engines in question were part of the older Internet Explorer architecture that has since been deprecated. Organizations should also implement monitoring solutions to detect anomalous script execution patterns that might indicate exploitation attempts. Regular security assessments and penetration testing should include verification of patched systems to ensure complete remediation of this memory corruption vulnerability.