CVE-2020-1060 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists in the way that the VBScript engine handles objects in memory, aka 'VBScript Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-1035, CVE-2020-1058, CVE-2020-1093.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability described in CVE-2020-1060 represents a critical remote code execution flaw within Microsoft's VBScript engine implementation. This vulnerability specifically targets how the scripting engine manages object references in memory, creating a pathway for malicious actors to execute arbitrary code on affected systems. The flaw exists in the underlying memory management mechanisms of VBScript processing, where improper handling of object lifecycles and memory references allows attackers to manipulate the execution flow of scripts. The vulnerability affects systems running Windows operating systems that have VBScript enabled and are exposed to untrusted web content or malicious scripts. Attackers can exploit this weakness by crafting specially designed VBScript code that triggers memory corruption during object manipulation, leading to arbitrary code execution with the privileges of the affected user. The vulnerability is particularly concerning because VBScript engines are commonly enabled in enterprise environments and web browsers, providing multiple attack vectors for exploitation. This issue is distinct from other related vulnerabilities such as CVE-2020-1035, CVE-2020-1058, and CVE-2020-1093, which address different aspects of scripting engine vulnerabilities but share the same underlying memory management flaws. The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-787, which covers out-of-bounds write vulnerabilities. From an operational perspective, this vulnerability enables attackers to perform privilege escalation, establish persistent access, and potentially compromise entire network infrastructures through lateral movement. The attack surface includes web browsers, email clients, and any application that processes VBScript content, making it a significant threat vector in enterprise environments where legacy applications may still rely on VBScript functionality. The vulnerability's impact is exacerbated by the fact that many organizations continue to support older Windows versions and legacy applications that have not been updated to address this specific memory management issue.
The exploitation of CVE-2020-1060 typically follows a pattern where attackers deliver malicious VBScript content through phishing emails, compromised websites, or malicious documents. The attack chain begins with the delivery of a payload that triggers the vulnerable VBScript engine, followed by memory corruption that allows the attacker to control the execution flow of the script processor. This vulnerability can be leveraged for initial access, privilege escalation, and persistence mechanisms within compromised systems. The memory corruption occurs during object reference handling when the VBScript engine fails to properly validate memory boundaries or object lifecycles, creating opportunities for attackers to inject malicious code that executes with the same privileges as the vulnerable application. Security researchers have identified that this vulnerability can be triggered through multiple vectors including web-based attacks, email attachments, and malicious documents that contain embedded VBScript code. The exploitation process often involves crafting specific memory layouts that cause the VBScript engine to write beyond allocated memory boundaries, resulting in controlled code execution. This vulnerability is particularly dangerous in enterprise environments where users may inadvertently execute malicious scripts through legitimate business processes or by visiting compromised websites that deliver the exploit. The attack can be automated and does not require user interaction beyond visiting a malicious website or opening a compromised document, making it highly effective for large-scale attacks. Organizations running vulnerable versions of Windows that have not applied the necessary security patches remain at significant risk of exploitation.
Mitigation strategies for CVE-2020-1060 focus on immediate patch deployment and operational security measures to reduce attack surface. Microsoft released security updates that address this vulnerability through patches to the VBScript engine and related components within Windows operating systems. Organizations should prioritize immediate deployment of these patches across all affected systems, particularly those running older Windows versions that are still in production use. Network segmentation and application whitelisting can provide additional layers of protection by limiting the execution of VBScript content to trusted applications and users. Security monitoring should include detection of suspicious VBScript execution patterns, memory access anomalies, and unusual network connections that may indicate exploitation attempts. Disabling VBScript support in web browsers and email clients can significantly reduce the attack surface, though this may impact legacy applications that depend on VBScript functionality. Endpoint detection and response solutions should be configured to monitor for indicators of compromise related to this vulnerability, including unusual memory allocation patterns and code execution from unexpected locations. The implementation of security awareness training for users can help prevent successful exploitation through social engineering attacks that deliver malicious VBScript content. Regular vulnerability assessments and penetration testing should be conducted to identify systems running outdated components that may still be vulnerable to this and similar memory corruption vulnerabilities. Organizations should also consider implementing zero-trust network architectures that limit the potential impact of successful exploitation by restricting lateral movement and access to critical resources. Compliance with security standards such as those outlined in the NIST Cybersecurity Framework and ISO 27001 can help ensure comprehensive protection against this and related vulnerabilities. The ATT&CK framework identifies this vulnerability under the technique T1059.005 for VBScript execution, making it important for security teams to understand the specific attack patterns associated with this threat. Regular security assessments and patch management processes should be implemented to ensure that all systems remain protected against this and similar memory corruption vulnerabilities that may be discovered in the future.