CVE-2017-9533 in IrfanView
Summary
by MITRE
IrfanView version 4.44 (32bit) with FPX Plugin 4.46 allows attackers to execute arbitrary code or cause a denial of service via a crafted .fpx file, related to a "User Mode Write AV starting at FPX!DE_Decode+0x0000000000000a9b."
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Analysis
by VulDB Data Team • 10/22/2019
The vulnerability identified as CVE-2017-9533 represents a critical heap-based buffer overflow flaw in IrfanView version 4.44 when utilizing the FPX Plugin version 4.46. This issue manifests through a user mode write access violation that occurs during the decoding process of crafted .fpx files, specifically at the FPX!DE_Decode+0x0000000000000a9b memory location. The flaw stems from inadequate input validation and memory management within the FPX file format parser, creating an exploitable condition that can be leveraged by malicious actors to execute arbitrary code or induce system crashes.
The technical exploitation of this vulnerability involves crafting a specially malformed .fpx file that triggers a buffer overflow during the decompression and decoding operations performed by the FPX plugin. When IrfanView processes such a file, the plugin fails to properly bounds-check data structures or validate the integrity of the input file format, allowing attackers to overwrite adjacent memory locations. This memory corruption can lead to unpredictable behavior including application crashes, memory corruption, or more dangerously, arbitrary code execution within the context of the IrfanView process. The vulnerability is particularly concerning because it operates within the user mode execution context, meaning successful exploitation could potentially escalate privileges or compromise the entire system.
From an operational impact perspective, this vulnerability creates significant security risks for users who may unknowingly open maliciously crafted image files, particularly in environments where IrfanView is commonly used for document viewing or image processing. The attack surface extends beyond simple exploitation to include social engineering campaigns where attackers distribute infected .fpx files through email attachments, malicious websites, or compromised file sharing platforms. Organizations relying on IrfanView for image processing workflows face potential data breaches, system compromise, or denial of service conditions that could disrupt business operations. The vulnerability's classification aligns with CWE-121, heap-based buffer overflow, and represents a clear violation of secure coding practices that should prevent such memory corruption scenarios.
Mitigation strategies for CVE-2017-9533 should prioritize immediate patching of IrfanView to version 4.45 or later, which includes fixes for the FPX plugin memory handling issues. System administrators should implement restrictive file type handling policies and consider disabling the FPX plugin entirely if it is not essential for operations. Network-level defenses such as email filtering and web content filtering should be enhanced to block suspicious .fpx files from entering the network perimeter. Additionally, endpoint protection solutions should be configured to monitor for unusual memory access patterns or process behavior that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation and proper memory management as outlined in the OWASP Top Ten and aligns with ATT&CK technique T1203 for exploitation of vulnerabilities in image processing applications. Regular security assessments and vulnerability scanning should be implemented to identify similar issues in other image processing libraries and applications that may be susceptible to similar buffer overflow conditions.