CVE-2015-6052 in Internet Explorer
Summary
by MITRE
The Microsoft (1) VBScript 5.7 and 5.8 and (2) JScript 5.7 and 5.8 engines, as used in Internet Explorer 8 through 11 and other products, allow remote attackers to bypass the ASLR protection mechanism via a crafted web site, aka "VBScript and JScript ASLR Bypass."
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Analysis
by VulDB Data Team • 06/21/2022
The vulnerability described in CVE-2015-6052 represents a critical security flaw in the scripting engines of Microsoft Internet Explorer that affects VBScript 5.7 and 5.8 as well as JScript 5.7 and 5.8 implementations. This vulnerability specifically targets the Address Space Layout Randomization protection mechanism, which is a fundamental security feature designed to prevent exploitation of memory corruption vulnerabilities by randomizing the memory layout of processes. The flaw allows remote attackers to bypass ASLR protections through carefully crafted web content, effectively neutralizing one of the primary defenses against exploit development.
The technical nature of this vulnerability stems from improper implementation of memory management within the scripting engines where the randomization values used for ASLR are predictable or can be manipulated by malicious actors. When Internet Explorer processes web content containing crafted scripting code, the VBScript and JScript engines fail to properly maintain the randomized memory layout that ASLR normally provides. This allows attackers to determine memory addresses of critical system components, making it significantly easier to execute successful exploits that would otherwise be prevented by ASLR. The vulnerability specifically affects Internet Explorer versions 8 through 11, though it may also impact other Microsoft products that utilize these scripting engines.
The operational impact of this vulnerability is substantial as it fundamentally undermines the security posture of affected systems by removing a critical defense mechanism that protects against memory corruption exploits. Attackers can leverage this bypass to execute arbitrary code on vulnerable systems with elevated privileges, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it affects widely deployed components of the Windows operating system, making it a prime target for exploitation in targeted attacks and malware campaigns. The bypass of ASLR means that attackers can more easily develop and deploy exploits that rely on memory layout predictions, significantly increasing the success rate of attacks against vulnerable systems.
Mitigation strategies for this vulnerability include immediate installation of Microsoft security updates that address the ASLR bypass in the scripting engines, along with implementing additional security measures such as enabling enhanced protection modes in Internet Explorer and deploying application whitelisting policies. Organizations should also consider disabling scripting engines in web browsers when not required for business operations, implementing network-based protections through firewalls and intrusion detection systems, and conducting regular security assessments to identify potentially affected systems. This vulnerability aligns with CWE-119, which describes weaknesses in memory management, and maps to ATT&CK technique T1059.005 for scripting, specifically targeting the execution of malicious scripts through web browsers to bypass security controls. The remediation process should also include comprehensive testing to ensure that the updates do not negatively impact legitimate business applications that depend on these scripting engines.