CVE-2019-1005 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists in the way the scripting engine handles objects in memory in Microsoft browsers, aka 'Scripting Engine Memory Corruption Vulnerability'. This CVE ID is unique from CVE-2019-0920, CVE-2019-0988, CVE-2019-1055, CVE-2019-1080.
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Analysis
by VulDB Data Team • 05/20/2025
This vulnerability represents a critical memory corruption issue within Microsoft's scripting engine that affects multiple browser environments including Internet Explorer and Microsoft Edge. The flaw manifests when the scripting engine improperly handles object references in memory, creating conditions where malicious code can manipulate memory layout and execute arbitrary instructions. The vulnerability specifically targets the way JavaScript and other scripting languages are interpreted and executed within the browser environment, making it particularly dangerous as it can be exploited through web-based attacks without requiring user interaction beyond visiting a malicious website. The memory corruption occurs during normal script execution flows when objects are created, modified, or destroyed in ways that bypass normal memory safety checks and validation mechanisms. This type of vulnerability falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions that can lead to memory corruption and arbitrary code execution. The ATT&CK framework categorizes this under T1059.007 for command and scripting interpreter, where adversaries can leverage scripting engines to execute malicious payloads through browser-based attack vectors.
The technical exploitation of this vulnerability requires careful manipulation of memory objects to overwrite critical execution pointers or jump tables within the scripting engine's memory space. Attackers typically craft malicious web pages containing specially designed JavaScript code that triggers the memory corruption when executed by the vulnerable browser. The flaw allows for privilege escalation from standard user context to system level execution, as the browser processes run with elevated privileges to handle web content. Memory layout randomization techniques that normally protect against such exploits are bypassed through precise control of object allocation patterns and memory access sequences. The vulnerability affects all supported versions of Internet Explorer and Microsoft Edge, with the most significant impact occurring when users browse to malicious websites or open specially crafted documents that trigger the scripting engine execution path. The exploitation process typically involves creating a memory layout that allows for controlled overwrite of function pointers or return addresses, enabling attackers to redirect execution flow to malicious code injected into the browser's memory space.
The operational impact of this vulnerability extends beyond simple remote code execution to include complete system compromise and data exfiltration capabilities. Once successfully exploited, attackers can install backdoors, modify system files, steal credentials, and maintain persistent access to affected systems. The vulnerability's presence in both Internet Explorer and Edge means that organizations with mixed browser environments face significant risk exposure, as attackers can target the most vulnerable browser in their environment. Security teams must implement immediate patch management procedures to address this vulnerability, as the window for exploitation remains open until patches are deployed. The vulnerability's remote nature makes it particularly attractive to threat actors, as it can be deployed at scale through phishing campaigns or compromised websites without requiring physical access to target systems. Organizations should implement network-based protections such as web application firewalls and content filtering to mitigate exposure while patches are being deployed, as the vulnerability can be exploited through standard web browsing activities.
Mitigation strategies should focus on immediate patch deployment combined with network segmentation and monitoring of suspicious browser activity. Microsoft released security updates that address the memory corruption issue through improved object handling and memory validation checks within the scripting engine. Organizations should also implement browser hardening measures including disabling unnecessary scripting features, implementing strict content security policies, and using sandboxing techniques to limit the potential impact of successful exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that reduce the attack surface available to threat actors. Security monitoring should include detection of unusual browser memory patterns and anomalous script execution behaviors that may indicate exploitation attempts. Regular security assessments and penetration testing should be conducted to identify additional vulnerabilities in browser environments and ensure that mitigation measures remain effective against evolving attack techniques.