CVE-2017-1000186 in SWFTools
Summary
by MITRE
In SWFTools, a stack overflow was found in pdf2swf.
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability identified as CVE-2017-1000186 represents a critical stack overflow condition within SWFTools, specifically affecting the pdf2swf utility. This flaw exists in the handling of malformed PDF files during the conversion process to Flash SWF format, creating a potential remote code execution vector that could be exploited by attackers. The vulnerability stems from insufficient input validation and memory management within the pdf2swf component, which processes PDF documents and converts them into flash-compatible formats for web deployment.
SWFTools is a widely used collection of command-line utilities designed for manipulating Flash SWF files, with pdf2swf serving as a crucial converter that transforms PDF documents into interactive Flash content. The stack overflow vulnerability manifests when the utility processes specially crafted PDF files containing malformed data structures that exceed the allocated stack buffer space. This condition occurs during the parsing of PDF objects and their subsequent conversion to SWF format, where the software fails to properly validate the size of input data before copying it into fixed-size stack buffers. The flaw is particularly concerning as it can be triggered through automated processing of PDF files, making it exploitable in web environments where PDF handling is common.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it presents a significant security risk that could enable remote code execution on systems running vulnerable versions of SWFTools. Attackers could craft malicious PDF files designed to trigger the stack overflow during the pdf2swf conversion process, potentially allowing them to execute arbitrary code with the privileges of the user running the utility. This vulnerability affects various operating systems including Linux, Windows, and macOS where SWFTools is installed, particularly in environments where PDF processing is automated or integrated into web applications. The exploitation of this vulnerability could lead to complete system compromise, data exfiltration, or deployment of additional malware within the affected infrastructure.
Security practitioners should consider this vulnerability in the context of CWE-121, which addresses stack-based buffer overflow conditions, and potentially CWE-787, which covers out-of-bounds writes in heap-based memory. The attack surface aligns with ATT&CK technique T1203, where adversaries leverage software vulnerabilities to execute code, and T1059, which involves the use of command and scripting interpreters. Organizations should prioritize immediate patching of affected SWFTools installations, implement input validation controls for PDF processing workflows, and consider network segmentation to limit exposure. Additionally, monitoring for unusual pdf2swf execution patterns and implementing application whitelisting controls can help detect and prevent exploitation attempts. The vulnerability underscores the importance of proper input validation and memory management in utility applications that process untrusted data, particularly in environments where automated processing of user-uploaded content occurs.