CVE-2013-3126 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 9 and 10, when script debugging is enabled, does not properly handle objects in memory during the processing of script, which allows remote attackers to execute arbitrary code via a crafted web site, aka "Internet Explorer Script Debug Vulnerability."
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Analysis
by VulDB Data Team • 05/14/2021
The vulnerability identified as CVE-2013-3126 represents a critical memory corruption flaw in Microsoft Internet Explorer versions 9 and 10 that specifically manifests when script debugging functionality is enabled. This vulnerability falls under the CWE-125 vulnerability type, which encompasses out-of-bounds read conditions that can lead to arbitrary code execution. The flaw occurs during the processing of script code within the browser's JavaScript engine, where improperly handled memory objects create exploitable conditions that adversaries can leverage to gain unauthorized code execution capabilities. The vulnerability is particularly concerning because it requires no user interaction beyond visiting a malicious website, making it a prime candidate for drive-by download attacks that can compromise systems without user awareness.
The technical implementation of this vulnerability stems from how Internet Explorer handles memory management during script debugging operations. When script debugging is active, the browser's scripting engine creates and manages objects in memory that do not undergo proper validation before being processed. This memory handling error creates a condition where attackers can craft malicious web content that triggers a buffer overflow or memory corruption scenario when the debugging process attempts to access improperly managed objects. The flaw essentially allows attackers to manipulate memory addresses and overwrite critical execution pointers, enabling them to inject and execute arbitrary code with the privileges of the compromised browser session. This vulnerability directly maps to the ATT&CK technique T1059.007 for Command and Scripting Interpreter, specifically targeting JavaScript execution environments.
The operational impact of CVE-2013-3126 extends beyond simple code execution, as it provides attackers with a foothold for more sophisticated attacks within the target environment. Successful exploitation can lead to complete system compromise, allowing attackers to install persistent backdoors, exfiltrate sensitive data, or establish command and control channels. The vulnerability's prevalence in widely deployed Internet Explorer versions 9 and 10 made it particularly dangerous in enterprise environments where these browsers were commonly used for business operations. Organizations running these vulnerable versions faced significant risk exposure, as the attack vector required minimal user interaction and could be effectively delivered through standard web browsing activities. The vulnerability also demonstrated the importance of secure coding practices in browser development, particularly around memory management and object lifecycle handling during debugging operations.
Mitigation strategies for CVE-2013-3126 primarily focus on disabling script debugging functionality in Internet Explorer, which effectively eliminates the attack surface associated with this vulnerability. Microsoft released security updates that addressed the memory handling issues in the JavaScript engine, but organizations needed to ensure timely deployment of these patches across their networks. Additional protective measures included implementing browser security policies that disabled script debugging in enterprise environments, utilizing network-based intrusion detection systems to monitor for exploitation attempts, and educating users about avoiding suspicious websites. The vulnerability highlighted the need for comprehensive browser hardening practices and demonstrated how seemingly benign debugging features could create significant security risks when not properly secured. Organizations should have implemented layered defense approaches including web application firewalls, content filtering solutions, and regular security assessments to detect and prevent exploitation attempts targeting this and similar vulnerabilities.