CVE-2017-14561 in STDU Viewer
Summary
by MITRE
STDU Viewer 1.6.375 allows attackers to execute arbitrary code or cause a denial of service via a crafted .xps file, related to an "Illegal Instruction Violation starting at Unknown Symbol @ 0x00000000048c024d called from STDUXPSFile!DllUnregisterServer+0x0000000000025638."
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 11/17/2019
The vulnerability identified as CVE-2017-14561 affects STDU Viewer version 1.6.375, a document viewing application that processes XPS (XML Paper Specification) files. This weakness represents a critical security flaw that can be exploited to achieve remote code execution or system denial of service through the manipulation of specially crafted XPS documents. The vulnerability stems from improper input validation and memory handling within the application's processing of XPS file structures, particularly during the registration and unregistration phases of the underlying DLL components.
The technical exploitation occurs through an illegal instruction violation that manifests at a specific memory address 0x00000000048c024d within the STDUXPSFile.dll module. This memory location corresponds to the DllUnregisterServer function, which is part of the Windows dynamic link library registration process. The vulnerability specifically triggers when the application attempts to process malformed XPS files that contain crafted instructions designed to exploit buffer overflows or memory corruption conditions. This type of flaw falls under CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations, both of which are common precursors to arbitrary code execution scenarios. The attack vector leverages the application's failure to properly validate the structure and content of XPS files before processing them, allowing malicious actors to inject code that executes with the privileges of the affected application.
The operational impact of this vulnerability extends beyond simple exploitation as it can lead to complete system compromise when users open maliciously crafted XPS files. Since STDU Viewer typically runs with user privileges, successful exploitation could enable attackers to execute malicious code, access sensitive system resources, or establish persistence mechanisms within the victim environment. The vulnerability's potential for denial of service creates additional operational risks, as it could be used to disrupt legitimate business operations or create system instability. This weakness aligns with ATT&CK technique T1203, which describes legitimate user execution, and T1059, covering command and scripting interpreter usage, as attackers could leverage the vulnerability to execute arbitrary commands through the compromised viewer application. Organizations using STDU Viewer in enterprise environments face significant risk exposure, particularly in scenarios where users might encounter malicious XPS files through email attachments, web downloads, or file sharing systems.
Mitigation strategies for CVE-2017-14561 should prioritize immediate software updates from the vendor, as version 1.6.375 contains the vulnerable code that requires patching. System administrators should implement application whitelisting policies to restrict execution of potentially malicious XPS files and establish strict file validation procedures for all document types. Network segmentation and firewall rules can help limit the attack surface by controlling access to systems that might process XPS documents. Additionally, user education programs should emphasize the importance of not opening suspicious files from untrusted sources, and security monitoring should be enhanced to detect anomalous behavior related to document viewer processes. Organizations should also consider implementing sandboxing techniques for document processing and regularly review their security configurations to ensure that legacy applications like STDU Viewer do not pose unnecessary risks to overall network security posture. The vulnerability demonstrates the importance of proper input validation and memory management practices in preventing exploitation of similar weaknesses in document processing applications.