CVE-2017-14947 in GSView
Summary
by MITRE
Artifex GSView 6.0 Beta on Windows allows attackers to execute arbitrary code or cause a denial of service via a crafted .xps file, related to a "Read Access Violation on Block Data Move starting at mupdfnet64!mIncrementalSaveFile+0x0000000000193359."
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 11/21/2019
CVE-2017-14947 represents a critical buffer overflow vulnerability in Artifex GSView 6.0 Beta for Windows systems that stems from improper handling of maliciously crafted XPS (XML Paper Specification) documents. This vulnerability specifically manifests as a read access violation during block data movement operations within the mupdfnet64.dll component, where the application fails to properly validate input data when processing incremental save file operations. The flaw occurs at the memory management level where the application attempts to move block data without adequate bounds checking, creating an exploitable condition that can be leveraged by remote attackers to execute arbitrary code or induce denial of service scenarios. The vulnerability is categorized under CWE-125 as an out-of-bounds read condition, which directly maps to the memory access violation pattern observed in this exploit.
The technical exploitation of this vulnerability requires an attacker to craft a malicious XPS file that triggers the specific memory access pattern during file processing. When GSView attempts to parse and handle the crafted document, the incremental save file functionality invokes the mIncrementalSaveFile function where the buffer overflow occurs at the address offset 0x193359 within the mupdfnet64 module. This particular memory access violation allows attackers to manipulate the program execution flow by overwriting critical memory locations, potentially leading to code execution with the privileges of the affected application. The vulnerability's impact is significant as it affects the core document processing functionality of GSView, making it a prime target for exploitation in phishing campaigns or malicious document delivery attacks.
From an operational perspective, this vulnerability presents a severe risk to organizations relying on GSView for document processing, particularly in environments where users may encounter untrusted XPS documents. The vulnerability can be exploited through various attack vectors including email attachments, web downloads, or file sharing platforms where malicious XPS files might be distributed. Attackers can leverage this flaw to execute arbitrary commands on vulnerable systems, potentially leading to full system compromise, data exfiltration, or establishment of persistent backdoors. The denial of service aspect of this vulnerability means that even successful exploitation without code execution can render the application unusable, causing operational disruptions and productivity losses for affected organizations.
Organizations should implement immediate mitigations including applying available patches from Artifex, disabling XPS file processing capabilities when possible, and implementing strict file validation policies for incoming documents. Network segmentation and email filtering solutions should be configured to block or scan XPS files before they reach end-user systems. The ATT&CK framework categorizes this vulnerability under T1203 - Exploitation for Client Execution and T1059 - Command and Scripting Interpreter, highlighting the attack techniques that leverage such memory corruption flaws. Additionally, organizations should consider implementing application whitelisting policies to restrict execution of GSView or similar applications, and deploy endpoint detection and response solutions to monitor for suspicious memory access patterns that may indicate exploitation attempts. Regular vulnerability assessments and security awareness training should be conducted to reduce the risk of successful exploitation through social engineering vectors.