CVE-2018-8964 in libming
Summary
by MITRE
In libming 0.4.8, the decompileDELETE function of decompile.c has a use-after-free. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted swf file.
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Analysis
by VulDB Data Team • 02/24/2023
The vulnerability identified as CVE-2018-8964 represents a critical use-after-free flaw within the libming library version 0.4.8, specifically within the decompileDELETE function located in the decompile.c source file. This library serves as a SWF (Small Web Format) file manipulation tool widely used for processing flash content, making it a significant target for exploitation in web-based environments. The flaw manifests when the library processes maliciously crafted SWF files, creating conditions where memory that has been freed is subsequently accessed, leading to unpredictable behavior and potential system instability.
The technical nature of this vulnerability places it squarely within the CWE-416 category of use-after-free conditions, which occur when a program continues to reference memory after it has been freed by the system. In the context of libming's decompileDELETE function, this occurs during the parsing and decompilation of SWF file structures where memory allocation and deallocation sequences are not properly synchronized. Attackers can exploit this by crafting specially designed SWF files that trigger the vulnerable code path, causing the application to access freed memory locations and potentially leading to application crashes or system instability.
From an operational impact perspective, this vulnerability creates a significant denial of service risk for systems that process SWF files through libming, including web applications, content management systems, and media processing platforms that rely on this library for flash content handling. The remote exploitation capability means that attackers can trigger the vulnerability from outside the target system, making it particularly dangerous in web-facing applications. The consequences extend beyond simple service interruption to potentially allowing for more sophisticated attacks if the memory corruption can be leveraged for arbitrary code execution, though the current analysis indicates primary impact is denial of service.
The attack surface for CVE-2018-8964 spans across various systems and applications that utilize libming for SWF processing, including web browsers with flash plugins, content delivery networks, and enterprise applications that handle flash-based media. Organizations using this library in production environments face potential operational disruptions, particularly those that process user-uploaded SWF content without proper validation. The vulnerability aligns with ATT&CK technique T1203 by enabling adversaries to gain access to systems through exploitation of software vulnerabilities, potentially leading to broader compromise if the affected systems are not properly isolated or patched.
Mitigation strategies for this vulnerability should prioritize immediate patching of libming to version 0.4.9 or later, which contains the necessary fixes for the use-after-free condition. System administrators should implement input validation and sanitization measures for all SWF file processing, including content type checking and size limitations. Network-based defenses should include filtering of SWF content at perimeter defenses, while application-level protections should enforce proper memory management practices and implement robust error handling for file processing operations. Organizations should also consider implementing sandboxing techniques for SWF file handling to contain potential impacts from exploitation attempts. The vulnerability demonstrates the importance of regular security updates and proper code review practices for libraries handling untrusted input data, particularly those with complex parsing requirements like multimedia file formats.