CVE-2018-5195 in NEO
Summary
by MITRE
Hancom NEO versions 9.6.1.5183 and earlier have a buffer Overflow vulnerability that leads remote attackers to execute arbitrary commands when performing the hyperlink Attributes in document.
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Analysis
by VulDB Data Team • 12/23/2019
The vulnerability identified as CVE-2018-5195 affects Hancom NEO document processing software versions 9.6.1.5183 and earlier, presenting a critical buffer overflow condition that can be exploited by remote attackers to achieve arbitrary code execution. This flaw specifically manifests when the application processes hyperlink attributes within document files, creating a pathway for malicious actors to manipulate memory structures and potentially gain unauthorized system access.
The technical implementation of this vulnerability stems from inadequate input validation within the hyperlink attribute processing module of Hancom NEO. When the software encounters malformed or specially crafted hyperlink data during document parsing, it fails to properly bounds-check the input data before copying it into fixed-size memory buffers. This classic buffer overflow condition allows attackers to overwrite adjacent memory locations, potentially corrupting program execution flow and enabling code injection attacks. The vulnerability operates at the application layer, requiring no local privileges to exploit and can be triggered through remote document delivery mechanisms.
From an operational perspective, this vulnerability presents significant risk to organizations relying on Hancom NEO for document processing, particularly in environments where users frequently open documents from external sources or receive email attachments. The remote exploit capability means that attackers can deliver malicious documents via phishing campaigns, compromised websites, or file sharing platforms without requiring physical access to target systems. Successful exploitation could result in complete system compromise, data exfiltration, or establishment of persistent backdoors within affected networks.
The vulnerability aligns with CWE-121, which categorizes buffer overflow conditions as critical software weaknesses that can lead to arbitrary code execution. This weakness maps to several ATT&CK tactics including execution through legitimate user processes and privilege escalation via exploitation of software vulnerabilities. Organizations should consider implementing network-based intrusion detection systems to monitor for exploitation attempts and maintain updated threat intelligence regarding similar vulnerabilities in office productivity suites.
Mitigation strategies should include immediate patch deployment for Hancom NEO versions 9.6.1.5183 and earlier, followed by network segmentation to limit exposure of vulnerable systems. Administrators should implement strict document validation policies, disable automatic hyperlink processing where possible, and conduct user awareness training to recognize potentially malicious document attachments. Additionally, endpoint protection solutions should be configured to monitor for suspicious process creation and memory manipulation patterns that could indicate exploitation attempts. Organizations should also consider implementing application whitelisting policies to restrict execution of untrusted document processing applications and maintain regular backup procedures to ensure rapid recovery from potential compromise scenarios.