CVE-2011-1331 in Ichitaro Viewer
Summary
by MITRE
JustSystems Ichitaro 2005 through 2011, Ichitaro Government 6, Ichitaro Government 2006 through 2010, Ichitaro Portable, Ichitaro Pro, and Ichitaro Viewer allow remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via a crafted document, as exploited in the wild in early 2011.
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Analysis
by VulDB Data Team • 07/16/2024
The vulnerability identified as CVE-2011-1331 represents a critical heap memory corruption flaw affecting multiple versions of JustSystems Ichitaro office suite applications including Ichitaro 2005 through 2011, Ichitaro Government 6, Ichitaro Government 2006 through 2010, Ichitaro Portable, Ichitaro Pro, and Ichitaro Viewer. This vulnerability operates at the core of document parsing mechanisms within these applications, where improper input validation and memory management practices create exploitable conditions that can be leveraged by remote attackers to gain unauthorized system access. The flaw manifests when these applications process specially crafted malicious documents that contain malformed data structures designed to trigger memory corruption during the parsing process, as demonstrated by actual exploitation activities that occurred in early 2011.
The technical nature of this vulnerability aligns with CWE-122, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to write data beyond allocated memory boundaries. This particular flaw enables attackers to manipulate heap memory structures through carefully constructed document elements that cause the application to allocate insufficient memory for processing certain data types. When the vulnerable applications attempt to parse these malicious documents, they encounter malformed input that triggers memory corruption patterns, potentially leading to arbitrary code execution or system crashes. The heap corruption occurs during document parsing operations, specifically when handling complex formatting elements, embedded objects, or structured data within the document files, making this vulnerability particularly dangerous as it can be triggered simply by opening a malicious document.
The operational impact of CVE-2011-1331 extends beyond simple denial of service scenarios to encompass full system compromise capabilities that align with ATT&CK technique T1203, which covers exploitation of remote services through memory corruption vulnerabilities. Organizations utilizing affected Ichitaro versions face significant risk exposure as attackers could leverage this vulnerability to execute malicious code on target systems, potentially establishing persistent access, exfiltrating sensitive data, or deploying additional malware payloads. The widespread adoption of Ichitaro in business and government environments, particularly in Japan where the software is popular, created substantial attack surface for threat actors who could exploit this vulnerability to target critical infrastructure and sensitive organizational data. The vulnerability's remote exploitability means that attackers do not require physical access to target systems and can deliver malicious documents through email attachments, web downloads, or other remote delivery mechanisms.
Mitigation strategies for this vulnerability require immediate patching of affected applications to address the heap memory corruption issues within the document parsing libraries. Organizations should implement comprehensive network security controls including email filtering solutions that can identify and block malicious document attachments, network segmentation to limit lateral movement, and endpoint protection measures that monitor for suspicious memory access patterns. System administrators should disable unnecessary document processing features and implement strict file type controls to prevent automatic execution of potentially malicious documents. The vulnerability also highlights the importance of regular security updates and vulnerability management processes, as this flaw was actively exploited in the wild shortly after its discovery, emphasizing the need for rapid response to newly identified security issues. Organizations should also consider implementing application whitelisting policies that restrict execution of untrusted document processing applications and maintain detailed monitoring of system memory usage patterns to detect potential exploitation attempts.