CVE-2019-9966 in XnView Classic
Summary
by MITRE
XnView Classic 2.48 on Windows allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted file, related to xnview+0x38536c.
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Analysis
by VulDB Data Team • 08/04/2023
CVE-2019-9966 represents a critical vulnerability in XnView Classic version 2.48 for Windows systems, where remote attackers can exploit a flaw in the application's file handling mechanism to trigger denial of service conditions or potentially execute arbitrary code. This vulnerability specifically manifests through a crafted file that, when processed by the application, causes an application crash at the memory address xnview+0x38536c. The flaw resides in the application's inability to properly validate and handle malformed input data during image file parsing operations.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions that occur when a program writes data beyond the boundaries of a heap-allocated buffer. In the context of XnView Classic, this manifests when the application attempts to parse maliciously constructed image files that contain oversized or malformed data structures. The vulnerability is particularly concerning because it can be exploited remotely without requiring any authentication or privileged access, making it highly attractive to threat actors seeking to disrupt services or gain unauthorized access to systems. The memory address xnview+0x38536c indicates a specific location within the application's memory space where the buffer overflow occurs, suggesting that the vulnerability is rooted in improper bounds checking within the image processing library.
From an operational impact perspective, this vulnerability creates significant risks for organizations that rely on XnView Classic for image management and viewing operations. The denial of service aspect can lead to complete application unavailability, disrupting legitimate user access and potentially causing business continuity issues. In some cases, the vulnerability may enable arbitrary code execution, which could allow attackers to gain full control over affected systems. This represents a serious threat vector that aligns with ATT&CK technique T1203, which covers legitimate user application execution through exploitation of application vulnerabilities. The vulnerability's remote exploitability means that attackers can target systems from outside the network perimeter, making traditional network-based security controls insufficient to prevent exploitation.
The mitigation strategies for CVE-2019-9966 should include immediate deployment of vendor-provided patches or updates to XnView Classic, as well as network-level controls to restrict access to the application where possible. Organizations should implement application whitelisting policies to prevent execution of untrusted files and establish robust monitoring for unusual application behavior that might indicate exploitation attempts. Security teams should also consider implementing network segmentation to isolate systems running vulnerable versions of the application and deploy intrusion detection systems that can identify patterns consistent with exploitation attempts. Additionally, regular vulnerability assessments and penetration testing should be conducted to identify similar vulnerabilities in other image processing applications and ensure comprehensive protection against similar attack vectors. The vulnerability serves as a reminder of the critical importance of proper input validation and memory safety practices in software development, particularly for applications that process untrusted data from external sources.