CVE-2017-9905 in XnView Classic
Summary
by MITRE
XnView Classic for Windows Version 2.40 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted .fpx file, related to "Data from Faulting Address controls Branch Selection starting at Xfpx!gffGetFormatInfo+0x00000000000228e8."
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Analysis
by VulDB Data Team • 10/23/2019
The vulnerability identified as CVE-2017-9905 affects XnView Classic for Windows version 2.40 and represents a critical remote code execution and denial of service flaw. This issue stems from improper handling of maliciously crafted .fpx files within the image processing framework of the application. The vulnerability specifically manifests when the application attempts to process a malformed file, leading to unpredictable behavior that can result in system instability or complete crash conditions. The root cause lies within the Xfpx!gffGetFormatInfo function where faulting address data directly influences branch selection logic, creating a potential pathway for attackers to manipulate execution flow. This type of vulnerability falls under the category of heap-based buffer overflows and memory corruption issues that are commonly classified as CWE-121, heap-based buffer overflow, and CWE-125, out-of-bounds read, according to the Common Weakness Enumeration standards. The attack vector requires remote exploitation through the delivery of a specially crafted .fpx file, which when opened by the vulnerable application triggers the exploitable condition.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it potentially enables attackers to execute arbitrary code on affected systems. When an attacker successfully exploits this vulnerability, they can cause the application to crash or potentially gain control over the system's execution flow. The flaw's location within the graphics processing pipeline makes it particularly dangerous since many users routinely open image files from untrusted sources, including email attachments, web downloads, and file sharing platforms. The vulnerability's characteristics align with ATT&CK technique T1203, "Exploitation for Client Execution," where adversaries leverage software vulnerabilities to execute malicious code on target systems. The specific function gffGetFormatInfo in the Xfpx module demonstrates a classic case of indirect jump or call manipulation where attacker-controlled data influences program control flow, creating a pathway for privilege escalation or complete system compromise. This vulnerability particularly affects enterprise environments where XnView Classic is widely deployed for image viewing and management purposes.
Mitigation strategies for CVE-2017-9905 should focus on immediate remediation through software updates provided by the vendor, as well as network-level defenses to prevent the delivery of malicious .fpx files. Organizations should implement strict file validation protocols and restrict the opening of image files from untrusted sources. System administrators should consider deploying application whitelisting solutions to prevent execution of vulnerable versions of XnView Classic. The vulnerability's nature suggests that memory corruption techniques may be employed by attackers, making stack protection mechanisms and address space layout randomization particularly important defensive measures. Security teams should monitor for exploitation attempts through network traffic analysis and endpoint detection systems that can identify unusual file processing behavior. Additionally, users should be educated about the risks of opening unknown image files and the importance of keeping software updated. The vulnerability demonstrates the importance of input validation in multimedia processing libraries and highlights the need for robust error handling in image format parsers. Organizations should also consider implementing sandboxing techniques for image viewing applications to isolate potential exploitation attempts and prevent lateral movement within the network environment.