CVE-2019-9113 in libming
Summary
by MITRE
Ming (aka libming) 0.4.8 has a NULL pointer dereference in the function getString() in the decompile.c file in libutil.a.
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Analysis
by VulDB Data Team • 09/08/2025
The vulnerability identified as CVE-2019-9113 affects the Ming library version 0.4.8, which is a popular open-source library for creating and manipulating SWF (Small Web Format) files used in Adobe Flash applications. This library serves as a crucial component in various software systems that handle Flash content, making it a potential target for exploitation in environments where Flash processing remains active despite its deprecation. The vulnerability manifests as a NULL pointer dereference within the getString() function located in the decompile.c file of the libutil.a library component, representing a critical flaw that can lead to application crashes and potentially more severe security implications.
The technical flaw occurs within the getString() function when processing certain malformed SWF input data, specifically when the function attempts to dereference a pointer that has not been properly initialized or validated. This NULL pointer dereference represents a classic software bug pattern that can be exploited to cause denial of service conditions or potentially enable more sophisticated attack vectors depending on the execution context. The vulnerability stems from inadequate input validation and error handling within the decompilation process, where the library fails to properly check for NULL values before attempting to access memory locations. This issue aligns with CWE-476, which specifically addresses NULL pointer dereference vulnerabilities, and demonstrates how improper memory management can create exploitable conditions in software libraries.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged by attackers to disrupt services or potentially execute arbitrary code in vulnerable environments. When an application using the affected Ming library processes maliciously crafted SWF files, the NULL pointer dereference can cause the application to terminate unexpectedly, leading to denial of service conditions that may affect legitimate users and system availability. In environments where the library is used in web applications or content processing systems, this vulnerability could be exploited to cause cascading failures or to disrupt critical business operations. The vulnerability's exploitation potential is particularly concerning in systems that automatically process user-uploaded Flash content or that serve as intermediaries in Flash content delivery pipelines, as it could enable attackers to target these systems directly.
Mitigation strategies for CVE-2019-9113 should prioritize immediate software updates to versions that have patched the NULL pointer dereference issue, as the maintainers of the Ming library have likely addressed this vulnerability in subsequent releases. Organizations should implement comprehensive input validation measures that prevent malformed SWF content from reaching the vulnerable library functions, particularly in systems that process untrusted Flash content. Additionally, deploying defensive programming practices such as pointer validation checks and implementing proper error handling within applications that utilize the Ming library can help prevent exploitation. The ATT&CK framework's T1499.004 technique for network denial of service can be relevant in understanding how this vulnerability might be leveraged for service disruption, while the broader category of T1203 for exploitation of remote services should be considered in threat modeling exercises. System administrators should also consider implementing network segmentation and access controls to limit exposure of systems that rely on the affected library, particularly in environments where Flash processing continues despite its security limitations.