CVE-2019-9969 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+0x385399.
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Analysis
by VulDB Data Team • 08/04/2023
CVE-2019-9969 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 parsing mechanism to trigger denial of service conditions or potentially execute arbitrary code. This vulnerability manifests through the processing of specially crafted files that cause the application to crash or behave unpredictably, creating a significant security risk for users who may unknowingly open maliciously formatted files. The specific technical indicator of 0x385399 points to a memory corruption issue within the xnview+ module that occurs during file handling operations, suggesting that the vulnerability stems from improper input validation or buffer overflow conditions in the image parsing routines. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and potentially CWE-125, indicating out-of-bounds read vulnerabilities that could allow attackers to manipulate memory locations and potentially execute malicious code.
The operational impact of this vulnerability extends beyond simple application crashes, as it could enable attackers to remotely compromise systems through social engineering tactics that trick users into opening malicious files. Attackers could distribute crafted files through email attachments, malicious websites, or file sharing platforms, where unsuspecting users might open them with XnView Classic, leading to system instability or potential code execution. This vulnerability particularly affects environments where XnView Classic is the default image viewer or where users frequently open files from untrusted sources, creating a significant attack surface for threat actors. The remote nature of the exploit means that attackers do not require local system access to exploit the vulnerability, making it particularly dangerous in enterprise environments where users may encounter malicious files in shared network drives or email systems.
From an attack framework perspective, this vulnerability maps to several ATT&CK techniques including T1203, which involves legitimate programs being used for code execution, and T1059, covering command and scripting interpreter usage. The attack chain typically involves initial access through file delivery mechanisms, followed by exploitation of the vulnerable file parsing functionality to achieve either denial of service or code execution. Organizations should implement layered security controls including email filtering, web application firewalls, and user education programs to mitigate the risk of exploitation. The vulnerability also highlights the importance of keeping software updated, as this issue was likely addressed in subsequent versions of XnView Classic through proper input validation and memory management improvements. System administrators should consider implementing application whitelisting policies to restrict the execution of vulnerable applications and monitor for unusual application crash patterns that might indicate exploitation attempts.
The technical exploitation of this vulnerability requires attackers to craft specific file formats that trigger the memory corruption at the 0x385399 address, indicating that the flaw exists in the application's handling of specific image format metadata or parsing logic. This suggests that the vulnerability is particularly sensitive to malformed image headers or corrupted data structures that cause the application to attempt to access memory locations outside of its allocated boundaries. The potential for unspecified other impacts indicates that attackers might be able to leverage this vulnerability for privilege escalation or information disclosure, depending on the execution context and system configuration. Security professionals should monitor for any indicators of compromise related to XnView Classic crashes or unusual system behavior, as these could signal exploitation attempts. The vulnerability underscores the necessity of robust input validation and secure coding practices in multimedia applications, where processing untrusted file formats creates inherent security risks that require careful attention to memory management and buffer handling procedures.