CVE-2017-9926 in SWFTools
Summary
by MITRE
In SWFTools 2013-04-09-1007 on Windows, png2swf allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted file, related to a "Read Access Violation starting at image00000000_00400000+0x000000000001b596."
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Analysis
by VulDB Data Team • 10/23/2019
The vulnerability identified as CVE-2017-9926 affects SWFTools version 2013-04-09-1007 on Windows systems, specifically within the png2swf utility. This tool is part of a suite of applications designed for converting various image formats into flash swf files, commonly used in web development and multimedia applications. The flaw manifests when processing specially crafted png image files that trigger memory access violations during the conversion process. The vulnerability presents a significant security concern as it can be exploited remotely by attackers who craft malicious png files, potentially leading to system instability or more severe consequences.
The technical root cause of this vulnerability stems from inadequate input validation and memory management within the png2swf utility. When processing a malformed png file, the application attempts to read from memory locations that are either invalid or unauthorized, resulting in what is termed a "Read Access Violation." The specific memory address mentioned in the vulnerability description indicates that the error occurs at image00000000_00400000+0x000000000001b596, suggesting a buffer overflow or memory corruption scenario. This type of vulnerability falls under CWE-125: "Out-of-bounds Read" and potentially CWE-787: "Out-of-bounds Write" depending on the exact execution path. The memory access violation occurs during the image processing phase, where the tool fails to properly validate the structure and boundaries of the incoming png file before attempting to parse its contents.
From an operational perspective, this vulnerability creates a substantial risk for organizations that utilize SWFTools in their web applications or content management systems. The remote exploitation capability means that attackers can potentially compromise systems simply by uploading or accessing malicious files without requiring any special privileges or user interaction beyond the initial file processing. The potential impacts extend beyond simple denial of service, as the unspecified other impacts mentioned in the vulnerability description could include arbitrary code execution, information disclosure, or system compromise. The vulnerability is particularly concerning in environments where automatic file processing occurs, such as web applications that accept user uploads or content management systems that automatically convert images. According to ATT&CK framework, this vulnerability maps to T1499.004: "Endpoint Denial of Service" and potentially T1059.007: "Command and Scripting Interpreter: JavaScript" if the exploitation leads to code execution in the target environment.
Organizations should implement immediate mitigations to address this vulnerability, including disabling or restricting access to the vulnerable png2swf utility until a patched version is available. The recommended approach involves updating to the latest version of SWFTools where the memory handling and input validation issues have been addressed. System administrators should also implement network segmentation and access controls to limit exposure of systems running vulnerable versions. Additionally, input validation should be strengthened at multiple layers including application-level filtering, network-level restrictions, and content scanning solutions. Security monitoring should be enhanced to detect unusual file processing activities or memory access patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper memory management and input validation in multimedia processing applications, highlighting how seemingly benign file format conversions can become attack vectors when proper security controls are not implemented. Organizations should also consider implementing sandboxing techniques for file processing operations to contain potential exploitation attempts and limit the impact of such vulnerabilities on the broader system infrastructure.