CVE-2018-1020 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists when Internet Explorer improperly accesses objects in memory, aka "Internet Explorer Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10. This CVE ID is unique from CVE-2018-0870, CVE-2018-0991, CVE-2018-0997, CVE-2018-1018.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/09/2021
The vulnerability described in CVE-2018-1020 represents a critical memory corruption flaw in Microsoft Internet Explorer that enables remote code execution attacks. This vulnerability specifically affects Internet Explorer versions 9, 10, and 11, making it a significant concern for organizations still maintaining legacy browser environments. The flaw occurs when the browser improperly handles object access in memory, creating opportunities for attackers to execute arbitrary code on affected systems. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-125, which describes out-of-bounds read conditions that can lead to memory corruption and arbitrary code execution. The vulnerability's classification aligns with ATT&CK technique T1203, which covers exploitation of remote services through memory corruption attacks.
The technical implementation of this vulnerability involves Internet Explorer's memory management subsystem failing to properly validate object references during memory operations. When processing certain web content, particularly maliciously crafted HTML or JavaScript, the browser's memory allocator may create or access invalid memory locations, leading to unpredictable behavior that attackers can exploit to gain full system control. This memory corruption typically manifests when the browser attempts to access objects that have been freed or improperly allocated, creating opportunities for code injection attacks. The flaw is particularly dangerous because it operates at the memory level, bypassing many traditional security controls and sandboxing mechanisms that protect against higher-level attacks. Attackers can leverage this vulnerability by delivering malicious web content through phishing campaigns, compromised websites, or malicious advertisements that trigger the vulnerable code path when users browse to affected pages.
The operational impact of CVE-2018-1020 extends beyond individual system compromise to potentially enable broader network infiltration and persistent threats. Once successfully exploited, attackers can establish persistent backdoors, escalate privileges, and move laterally within networks to access additional systems and data. The vulnerability's remote execution capability means that attackers do not require physical access or local credentials to exploit affected systems, making it particularly attractive for large-scale attacks. Organizations running unsupported versions of Internet Explorer face heightened risk, as Microsoft has ceased providing security updates for these older browser versions, leaving them vulnerable to exploitation. The attack surface is significantly expanded when considering that many enterprise environments still maintain legacy Internet Explorer installations for compatibility reasons with older web applications and internal systems.
Mitigation strategies for CVE-2018-1020 should prioritize immediate remediation through security patches and updates from Microsoft, though organizations with legacy systems may need to implement additional protective measures. The most effective defense involves transitioning away from unsupported Internet Explorer versions to modern browsers that receive regular security updates and have more robust memory protection mechanisms. Organizations should implement network segmentation and web filtering controls to prevent access to potentially malicious websites that could exploit this vulnerability. Browser hardening techniques including disabling unnecessary features, implementing strict content security policies, and enabling sandboxing mechanisms can provide additional protection layers. Security monitoring should focus on detecting anomalous network traffic patterns and unusual system behavior that might indicate exploitation attempts. According to industry best practices, organizations should also consider implementing exploit prevention technologies and maintaining comprehensive incident response plans specifically addressing memory corruption vulnerabilities. Regular security assessments and vulnerability scanning should include checks for legacy Internet Explorer installations to ensure complete remediation across all affected systems.