CVE-2018-15871 in libming
Summary
by MITRE
An invalid memory address dereference was discovered in decompileSingleArgBuiltInFunctionCall in libming 0.4.8 before 2018-03-12. The vulnerability causes a segmentation fault and application crash, which leads to denial of service.
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Analysis
by VulDB Data Team • 05/04/2023
The vulnerability identified as CVE-2018-15871 represents a critical memory safety issue within the libming library version 0.4.8 and earlier releases. This library serves as a SWF (Shockwave Flash) file manipulation toolkit that allows developers to create and modify flash content programmatically. The flaw manifests in the decompileSingleArgBuiltInFunctionCall function which processes built-in function calls during the decompilation of SWF files. This function fails to properly validate memory addresses before dereferencing them, creating a condition where arbitrary memory locations may be accessed without proper bounds checking. The vulnerability specifically affects the handling of single-argument built-in function calls during the decompilation process, making it particularly dangerous when processing malformed or malicious SWF files that contain crafted function calls designed to exploit this weakness.
The technical exploitation of this vulnerability results in an invalid memory address dereference that ultimately leads to a segmentation fault and subsequent application crash. This type of flaw falls under the CWE-476 category of NULL Pointer Dereference, though more specifically relates to improper memory management and address validation within the decompilation routine. When the application attempts to access memory at an invalid address, the operating system terminates the process with a segmentation fault, effectively causing a denial of service condition. The vulnerability is particularly concerning because it can be triggered through normal file processing operations, meaning that any application using libming to process SWF files could be susceptible to this attack vector. The timing of the vulnerability disclosure on March 12, 2018, indicates that this flaw had been present in the codebase for some time before being identified and patched.
The operational impact of CVE-2018-15871 extends beyond simple application crashes to potentially enable more sophisticated attack scenarios. Systems that rely on libming for SWF file processing, including content management systems, web applications, and multimedia processing platforms, face significant risk from this vulnerability. Attackers could leverage this flaw to cause denial of service against services that process user-uploaded SWF files, effectively disrupting legitimate operations. The vulnerability is particularly dangerous in web environments where untrusted SWF content is processed, as it could allow remote attackers to crash services and potentially cause availability issues for critical infrastructure. Additionally, this type of memory corruption vulnerability may serve as a stepping stone for more advanced exploitation techniques, though the immediate impact is primarily focused on service disruption rather than arbitrary code execution.
Mitigation strategies for CVE-2018-15871 primarily involve updating to the patched version of libming released on March 12, 2018, which addresses the invalid memory address dereference in the decompileSingleArgBuiltInFunctionCall function. Organizations should prioritize patching affected systems and applications that utilize libming, particularly those handling SWF file processing. Additionally, implementing input validation measures and sanitization of SWF files before processing can provide defense-in-depth protection. Security teams should consider deploying runtime protections such as address space layout randomization and stack canaries to reduce the effectiveness of potential exploitation attempts. The vulnerability also highlights the importance of regular security audits and code reviews, particularly for libraries handling binary file formats where memory safety is paramount. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique of Network Denial of Service, as it enables attackers to disrupt services through application crashes, and potentially to T1059.007 for execution through script-based file processing. Organizations should also implement monitoring for unusual application crash patterns and segmentation fault occurrences that might indicate exploitation attempts.