CVE-2017-9907 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 "Possible Stack Corruption starting at Xfpx!gffGetFormatInfo+0x0000000000022e1f."
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Analysis
by VulDB Data Team • 10/23/2019
CVE-2017-9907 represents a critical stack corruption vulnerability affecting XnView Classic for Windows version 2.40 that enables remote attackers to execute denial of service attacks or potentially achieve arbitrary code execution through maliciously crafted .fpx files. This vulnerability stems from improper input validation within the Xfpx!gffGetFormatInfo function where stack corruption occurs at offset 0x0000000000022e1f, making it a prime target for exploitation by threat actors seeking to disrupt system operations or gain unauthorized access to affected systems.
The technical flaw manifests in the handling of .fpx file format parsing where the application fails to properly validate or sanitize input data before processing. When a maliciously crafted .fpx file is loaded, the Xfpx!gffGetFormatInfo function attempts to parse the malformed data structure, leading to stack corruption that can result in application crashes or potentially allow attackers to execute arbitrary code. This vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a critical weakness in software security where data written to a stack buffer exceeds the buffer's capacity, overwriting adjacent memory locations including return addresses and function parameters.
From an operational perspective, this vulnerability presents significant risk to organizations utilizing XnView Classic for image processing tasks, particularly in environments where users may encounter untrusted image files from external sources. The remote attack vector means that adversaries can exploit this vulnerability without requiring physical access to target systems, making it particularly dangerous in web-based environments or when users download images from untrusted sources. The potential for unspecified other impacts suggests that beyond simple denial of service, attackers may be able to leverage this vulnerability for privilege escalation or information disclosure attacks, depending on the execution environment and system configurations.
The attack surface for this vulnerability extends across multiple operational domains including enterprise environments, web applications, and user workstations where XnView Classic is installed. Attackers can potentially exploit this through phishing campaigns, malicious websites, or compromised file sharing platforms where .fpx files are distributed. Organizations should consider implementing network segmentation and access controls to limit exposure, while also monitoring for suspicious file downloads or execution patterns that may indicate exploitation attempts. The vulnerability also aligns with ATT&CK technique T1203, which involves gaining access to systems through exploitation of remote services, and T1059, which covers the execution of malicious code through various attack vectors.
Mitigation strategies should include immediate patching of XnView Classic to version 2.41 or later where the vulnerability has been addressed through proper input validation and memory management controls. System administrators should also implement file type restrictions and content filtering mechanisms to prevent execution of potentially malicious .fpx files, particularly in high-risk environments. Additionally, users should be educated about the dangers of opening untrusted image files and organizations should consider deploying sandboxing solutions to isolate image processing activities. Regular security assessments and vulnerability scanning should be conducted to identify any other instances of similar vulnerabilities within the organization's software inventory, particularly in legacy applications that may not receive regular security updates. The remediation process should also include monitoring network traffic for suspicious file transfers and implementing application whitelisting policies to prevent execution of unapproved image processing applications that may be vulnerable to similar stack corruption attacks.