CVE-2018-6315 in libming
Summary
by MITRE
The outputSWF_TEXT_RECORD function (util/outputscript.c) in libming through 0.4.8 is vulnerable to an integer overflow and resultant out-of-bounds read, which may allow attackers to cause a denial of service or unspecified other impact via a crafted SWF file.
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Analysis
by VulDB Data Team • 02/02/2023
The vulnerability identified as CVE-2018-6315 affects the libming library version 0.4.8 and earlier, specifically within the outputSWF_TEXT_RECORD function located in util/outputscript.c. This library serves as a SWF (Small Web Format) file generation library that allows developers to create flash content programmatically. The flaw manifests as an integer overflow condition that leads to an out-of-bounds read operation when processing specially crafted SWF files. The vulnerability represents a critical security weakness that can be exploited by malicious actors to manipulate the library's behavior during SWF file processing. The integer overflow occurs when the function handles text record data structures within SWF files, where improper input validation allows attackers to specify values that exceed the expected integer range, causing the application to allocate insufficient memory or access memory regions beyond the intended boundaries. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow conditions that can result in memory corruption and arbitrary code execution. The out-of-bounds read operation can potentially expose sensitive memory contents or cause the application to crash, leading to denial of service conditions that affect legitimate users of systems relying on libming for SWF generation. From an operational perspective, this vulnerability impacts any system or application that utilizes libming to process or generate SWF files, including web applications, content management systems, and multimedia processing platforms. The attack surface expands when considering that SWF files were widely used for web content delivery, making this vulnerability particularly dangerous in environments where untrusted SWF content is processed. The security implications extend beyond simple denial of service to potentially enable more sophisticated attacks depending on the execution environment and memory layout. The vulnerability aligns with ATT&CK technique T1203, which involves the exploitation of software vulnerabilities to gain unauthorized access or cause system instability. The integer overflow creates a condition where attacker-controlled data can manipulate memory allocation decisions, potentially leading to information disclosure or system compromise. In terms of mitigation strategies, the primary recommendation involves upgrading to libming version 0.4.9 or later, which contains the necessary patches to address the integer overflow issue. Additionally, input validation should be implemented at all levels where SWF files are processed, ensuring that text record data structures are properly bounded and validated before being passed to the vulnerable function. Network-level defenses such as content filtering and sandboxing mechanisms can also provide additional protection layers, particularly in environments where SWF file processing is required but cannot be immediately patched. Organizations should also consider implementing memory protection mechanisms like address space layout randomization and stack canaries to reduce the effectiveness of potential exploitation attempts. The vulnerability demonstrates the importance of rigorous input validation and proper integer handling in security-critical libraries, highlighting how seemingly minor implementation flaws can result in significant security risks in widely-used software components.