CVE-2017-2791 in Ichitaro Office
Summary
by MITRE
JustSystems Ichitaro 2016 Trial contains a vulnerability that exists when trying to open a specially crafted PowerPoint file. Due to the application incorrectly handling the error case for a function's result, the application will use this result in a pointer calculation for reading file data into. Due to this, the application will read data from the file into an invalid address thus corrupting memory. Under the right conditions, this can lead to code execution under the context of the application.
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Analysis
by VulDB Data Team • 09/02/2020
The vulnerability identified as CVE-2017-2791 affects JustSystems Ichitaro 2016 Trial, a document processing application that includes compatibility with Microsoft PowerPoint files. This flaw represents a classic buffer overflow condition that occurs during file parsing operations, specifically when handling malformed PowerPoint documents. The vulnerability stems from improper error handling within the application's file processing logic, creating a dangerous scenario where application state becomes corrupted during normal file operations. The issue manifests when the application attempts to open a specially crafted PowerPoint file that contains malformed data structures designed to trigger the vulnerable code path.
The technical root cause of this vulnerability lies in how the application manages function return values during file parsing operations. When the application processes a malformed PowerPoint file, it encounters an error condition within a critical parsing function. Rather than properly handling this error case and terminating the operation safely, the application proceeds to use the erroneous function result in pointer arithmetic calculations. This fundamental flaw in error handling creates a situation where memory addresses become invalid or improperly calculated, leading to data being written to locations outside the intended memory boundaries. The vulnerability specifically targets the pointer calculation mechanism used for reading file data, transforming what should be a safe file parsing operation into a memory corruption event.
The operational impact of this vulnerability extends beyond simple application instability, presenting a significant security risk that could enable remote code execution. When the application attempts to read data from the specially crafted PowerPoint file, it calculates memory addresses based on the erroneous function result, causing data to be written to invalid memory locations. This memory corruption can result in application crashes, but more critically, under specific conditions, it can be exploited to execute arbitrary code within the context of the application process. The attack vector requires the user to open a malicious PowerPoint file, making this a user-initiated privilege escalation vulnerability that could be delivered through social engineering campaigns or compromised email attachments.
This vulnerability maps directly to CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations. The flaw demonstrates characteristics consistent with the attack pattern described in MITRE ATT&CK technique T1203, where adversaries leverage application vulnerabilities to execute malicious code. The memory corruption aspect of this vulnerability aligns with the broader category of memory safety issues that have historically been exploited in document processing applications, particularly those handling complex file formats like PowerPoint. The specific nature of the vulnerability suggests it could be exploited through techniques involving controlled memory layout manipulation, potentially allowing for stack or heap-based code execution within the application's security context.
Mitigation strategies for this vulnerability should focus on immediate patching of the affected application, as the vendor has likely released a security update addressing the memory handling error. System administrators should implement application whitelisting policies to restrict execution of potentially vulnerable applications and consider deploying sandboxing solutions for document processing tasks. Network-level protections such as email filtering and web proxy configurations can help prevent users from accessing malicious PowerPoint files. Additionally, users should be educated about the risks of opening untrusted document files, particularly those received through email or downloaded from unverified sources. Regular security assessments of document processing applications and comprehensive vulnerability scanning should be implemented to identify similar memory corruption issues in other software components. The vulnerability underscores the importance of proper error handling in file parsing operations and the critical need for memory safety validation in applications that process external data files.