CVE-2012-2523 in JScript
Summary
by MITRE
Integer overflow in Microsoft Internet Explorer 8 and 9, JScript 5.8, and VBScript 5.8 on 64-bit platforms allows remote attackers to execute arbitrary code by leveraging an incorrect size calculation during object copying, aka "JavaScript Integer Overflow Remote Code Execution Vulnerability."
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Analysis
by VulDB Data Team • 03/27/2021
The vulnerability identified as CVE-2012-2523 represents a critical integer overflow flaw affecting Microsoft Internet Explorer 8 and 9 versions, along with JScript 5.8 and VBScript 5.8 components on 64-bit systems. This vulnerability stems from improper handling of size calculations during object copying operations within the scripting engines that power web browser functionality. The flaw manifests specifically on 64-bit platforms where the integer overflow conditions can be exploited to manipulate memory allocation and execution flow, creating opportunities for remote code execution attacks. Security researchers have classified this issue under CWE-190, which denotes integer overflow conditions that can lead to memory corruption and arbitrary code execution.
The technical mechanism behind this vulnerability involves the manipulation of integer values during memory allocation processes when copying JavaScript objects. When JScript or VBScript processes object duplication operations, it calculates the required memory space using integer arithmetic that fails to properly validate or handle cases where the calculated size exceeds the maximum representable value for the integer type. This overflow condition results in the allocation of insufficient memory, which can then be overwritten or manipulated by malicious code. The attack vector leverages the browser's scripting engines to execute crafted JavaScript or VBScript code that triggers the overflow condition, ultimately allowing attackers to gain control over the affected system. This vulnerability directly maps to ATT&CK technique T1059.007 for JavaScript and T1059.001 for command and scripting interpreter, with the exploitation occurring through browser-based attack surfaces.
The operational impact of CVE-2012-2523 is severe and far-reaching, as it enables remote attackers to execute arbitrary code on vulnerable systems without requiring user interaction beyond visiting a malicious website. The vulnerability affects organizations running Internet Explorer 8 and 9 on 64-bit architectures, which were widely deployed in enterprise environments during the affected period. Attackers can leverage this flaw to install malware, establish persistent backdoors, or escalate privileges within the compromised system. The exploitability of this vulnerability is enhanced by the fact that it requires no user interaction, making it particularly dangerous for targeted attacks against corporate networks. Organizations with legacy Internet Explorer deployments face significant risk exposure, as the vulnerability can be triggered through standard web browsing activities, potentially compromising sensitive corporate data and systems.
Mitigation strategies for CVE-2012-2523 primarily focus on immediate patch deployment and browser security hardening measures. Microsoft released security updates that addressed the integer overflow conditions in the affected scripting engines, and organizations should prioritize applying these patches to eliminate the vulnerability. System administrators should consider implementing browser security policies that disable unnecessary scripting features or restrict the execution of potentially malicious code. Additional protective measures include network segmentation, web application firewalls, and enhanced monitoring for suspicious network traffic patterns that may indicate exploitation attempts. Security teams should also implement regular vulnerability assessments to identify and remediate similar integer overflow conditions in other software components, as this class of vulnerability remains common in software development. The remediation process should also include user education regarding safe browsing practices and the importance of keeping software up to date with security patches. Organizations should also consider transitioning away from legacy browser versions that are no longer supported by vendors, as these systems present ongoing security risks that cannot be fully mitigated through patching alone.