CVE-2007-6436 in Ichitaro
Summary
by MITRE
Stack-based buffer overflow in JSGCI.DLL in JustSystems Ichitaro 2005, 2006, and 2007 allows user-assisted remote attackers to execute arbitrary code via a crafted document, as actively exploited in December 2007 by the Tarodrop.F trojan. NOTE: some of these details are obtained from third party information.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/20/2024
The CVE-2007-6436 vulnerability represents a critical stack-based buffer overflow in the JSGCI.DLL component of JustSystems Ichitaro office suite versions 2005, 2006, and 2007. This vulnerability stems from improper input validation within the document parsing functionality that processes specific file formats. The flaw occurs when the application encounters malformed or specially crafted document structures that exceed the allocated stack buffer space, creating conditions where adjacent memory regions can be overwritten with attacker-controlled data. The vulnerability is particularly dangerous because it operates within the context of document processing, making it susceptible to exploitation through user-assisted remote attacks where victims must open a maliciously crafted document for the exploit to succeed.
The technical implementation of this buffer overflow demonstrates a classic stack corruption vulnerability that aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite stack data. The vulnerability specifically affects the JavaScript engine component within Ichitaro's document processing pipeline, where JSGCI.DLL serves as the JavaScript execution environment. When processing malformed documents, the application fails to properly validate the size of input data before copying it into fixed-size stack buffers, creating a predictable memory corruption scenario. Attackers can leverage this vulnerability by crafting documents that contain oversized data structures or malformed JavaScript code that triggers the buffer overflow during normal document parsing operations.
The operational impact of CVE-2007-6436 was severe and demonstrated through its active exploitation in the Tarodrop.F trojan malware campaign during December 2007. This trojan specifically targeted the vulnerability by delivering malicious documents that, when opened by unsuspecting users, would trigger the buffer overflow and subsequently execute arbitrary code on the victim's system. The exploitation process typically involved crafting documents that contained carefully constructed JavaScript code or binary data that would overflow the stack buffer and redirect execution flow to malicious payload code. The vulnerability's exploitation required user interaction, as the document needed to be opened by the victim, but once executed, it provided attackers with full system compromise capabilities. This attack vector aligns with ATT&CK technique T1204.002, which describes user execution of malicious files through social engineering or document-based attacks.
The exploitation of this vulnerability highlights the broader security implications of inadequate input validation in office productivity software and the dangerous potential for remote code execution through document processing. Organizations running affected versions of Ichitaro were particularly vulnerable because the vulnerability existed within the core document processing functionality that users frequently interacted with. The attack surface was expanded by the widespread use of these office suite versions in enterprise environments, where users might receive malicious documents through email attachments or other common attack vectors. Security researchers noted that the vulnerability was particularly challenging to detect and prevent because it occurred during normal application operation rather than during explicit security-related functions, making it difficult for traditional security controls to identify the malicious activity.
Mitigation strategies for CVE-2007-6436 primarily focused on immediate software updates and patches provided by JustSystems, as well as organizational security measures to prevent document-based attacks. System administrators were advised to implement strict document filtering policies that prevented users from opening documents from untrusted sources, particularly those containing executable content or JavaScript. The vulnerability also underscored the importance of keeping office productivity software updated and implementing layered security approaches such as application whitelisting, sandboxing document processing, and network-based intrusion detection systems. Additionally, user education programs became crucial in helping employees recognize potentially malicious documents and understand the risks associated with opening unexpected attachments or documents from unknown sources. Organizations should have implemented comprehensive vulnerability management processes to identify and remediate similar issues in their software inventory, as the vulnerability's exploitation demonstrated the critical need for robust input validation in all software components that process external data.