CVE-2017-9925 in SWFTools
Summary
by MITRE
In SWFTools 2013-04-09-1007 on Windows, png2swf allows remote attackers to execute arbitrary code or cause a denial of service via a crafted file, related to a "User Mode Write AV near NULL starting at wow64!Wow64NotifyDebugger+0x000000000000001d."
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Analysis
by VulDB Data Team • 10/23/2019
The vulnerability identified as CVE-2017-9925 affects SWFTools version 2013-04-09-1007 on Windows systems, specifically within the png2swf utility. This flaw represents a critical security issue that enables remote attackers to achieve arbitrary code execution or cause denial of service conditions through the manipulation of crafted input files. The vulnerability manifests during the processing of PNG image files when converted to SWF format, highlighting a significant weakness in the input validation and memory management mechanisms of the software.
The technical root cause of this vulnerability stems from a user mode write access violation near NULL memory location, specifically occurring at wow64!Wow64NotifyDebugger+0x000000000000001d. This indicates that the vulnerability exists within the Windows WOW64 subsystem, which handles the execution of 32-bit applications on 64-bit Windows systems. The flaw occurs when the png2swf utility attempts to process malformed PNG files that trigger improper memory handling, leading to a null pointer dereference scenario. This type of vulnerability falls under CWE-476, which specifically addresses NULL pointer dereference conditions that can lead to system instability and potential code execution.
The operational impact of CVE-2017-9925 extends beyond simple denial of service, as it provides attackers with the capability to execute arbitrary code on affected systems. This represents a severe security risk that could allow attackers to gain unauthorized access, install malware, or compromise entire systems. The vulnerability's remote exploitability means that attackers do not require local access to the system, making it particularly dangerous in networked environments where SWFTools might be used for file conversion services. The attack vector through crafted PNG files makes this vulnerability particularly insidious as it can be triggered through normal file processing operations, potentially affecting web applications or automated systems that convert user-uploaded images.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1203, which involves exploitation of remote services for code execution. The flaw demonstrates how legacy software tools can contain critical vulnerabilities that persist for years, emphasizing the importance of regular security assessments and updates. Organizations utilizing SWFTools or similar conversion utilities should immediately implement mitigations including input validation, sandboxed processing environments, and network segmentation to prevent exploitation. The vulnerability also highlights the need for proper memory management practices and input sanitization in software development, particularly for applications that process untrusted file formats. Given the age of the affected SWFTools version, this vulnerability serves as a reminder of the risks associated with using outdated software components that may contain unpatched security flaws.