CVE-2019-1208 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-2019-1236.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/19/2020
The vulnerability described in CVE-2019-1208 represents a critical remote code execution flaw within Microsoft's VBScript engine implementation. This vulnerability specifically targets how the engine manages objects in memory, creating a pathway for attackers to execute arbitrary code on affected systems. The issue stems from improper handling of object references and memory allocation within the scripting environment, which allows malicious actors to manipulate the engine's behavior through carefully crafted script content. The vulnerability affects systems running Windows operating systems that have VBScript enabled and are exposed to untrusted input sources. This particular flaw is distinct from CVE-2019-1236, indicating that while both vulnerabilities involve scripting engines, they target different aspects of the VBScript implementation and require separate mitigation approaches.
The technical exploitation of this vulnerability occurs through memory corruption techniques that leverage the VBScript engine's object management mechanisms. Attackers can construct malicious VBScript code that triggers buffer overflows, use-after-free conditions, or other memory manipulation patterns when the engine processes these scripts. The flaw typically manifests when the engine attempts to handle objects with malformed or unexpected memory structures, leading to unpredictable behavior that can be leveraged for code execution. This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, as the memory management issues can result in both read and write operations occurring beyond allocated memory boundaries. The exploitation process often involves crafting specific VBScript payloads that can be delivered through various attack vectors including web browsers, email attachments, or malicious websites that execute VBScript code in the context of the vulnerable system.
The operational impact of CVE-2019-1208 extends beyond simple remote code execution, as successful exploitation can lead to complete system compromise and persistent access for attackers. Once executed, malicious code can establish backdoors, escalate privileges, exfiltrate sensitive data, or deploy additional malware payloads. The vulnerability is particularly dangerous because VBScript engines are commonly enabled by default in Windows environments, making the attack surface broad and accessible to threat actors with minimal technical expertise. Organizations running affected systems face significant risk of data breaches, system infiltration, and potential lateral movement within their networks. The vulnerability's remote nature means that attackers can exploit it without requiring physical access to the target systems, making it particularly attractive for large-scale attacks. This aligns with ATT&CK technique T1059.005, which covers VBScript and WSH execution, and demonstrates how scripting engines can serve as attack vectors for broader compromise operations.
Mitigation strategies for CVE-2019-1208 should focus on both immediate patching and operational security measures. Microsoft released security updates that address the memory handling issues within the VBScript engine, and organizations must apply these patches promptly to eliminate the vulnerability. System administrators should also consider disabling VBScript execution where possible, particularly in web environments where scripting engines are often exposed to untrusted content. Network segmentation and application whitelisting can provide additional protection layers, while monitoring for suspicious VBScript execution patterns can help detect potential exploitation attempts. Security teams should implement comprehensive vulnerability management processes that include regular assessment of scripting engine usage across all systems and applications. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that reduce the attack surface for scripting-based exploits, as these vulnerabilities can persist in environments where legacy applications require scripting engine support.