CVE-2018-12109 in Free Lossless Image Format
Summary
by MITRE
An issue was discovered in Free Lossless Image Format (FLIF) 0.3. The TransformPaletteC<FileIO>::process function in transform/palette_C.hpp allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted PAM image file.
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Analysis
by VulDB Data Team • 03/22/2023
The vulnerability identified as CVE-2018-12109 resides within the Free Lossless Image Format (FLIF) 0.3 implementation, specifically within the TransformPaletteC<FileIO>::process function located in transform/palette_C.hpp. This flaw represents a critical security issue that affects the image processing capabilities of FLIF software, which is designed for lossless image compression and decompression. The vulnerability manifests when the software processes specially crafted PAM image files, which are part of the portable anymap format family used for storing images. The flaw stems from inadequate input validation and memory management within the palette transformation processing logic, creating a scenario where malformed image data can trigger unexpected behavior in the application's memory handling mechanisms.
The technical exploitation of this vulnerability occurs through a heap-based buffer overflow condition that arises when the TransformPaletteC<FileIO>::process function attempts to handle crafted PAM image data. This buffer overflow vulnerability is classified under CWE-121 as a stack-based buffer overflow, though the heap-based nature indicates the memory corruption occurs in the heap rather than stack memory regions. The overflow occurs because the function fails to properly validate the size of data elements within the PAM file before attempting to allocate or copy memory for palette processing operations. When an attacker provides a malicious PAM file with manipulated header values or palette data, the function processes these values without adequate bounds checking, leading to memory corruption that can result in application crashes or potentially more severe consequences depending on the execution environment.
The operational impact of this vulnerability extends beyond simple denial of service, as the heap-based buffer overflow could potentially be leveraged for more sophisticated attacks depending on the system configuration and memory layout. Remote attackers can exploit this vulnerability by preparing a crafted PAM image file and delivering it to a victim who uses FLIF software for image processing or viewing. The application crash resulting from the buffer overflow effectively renders the software unusable for legitimate image processing tasks, creating a denial of service condition that can be particularly problematic in automated systems or environments where image processing is critical. The unspecified other impacts mentioned in the vulnerability description suggest potential for additional security consequences that could include information disclosure, privilege escalation, or arbitrary code execution depending on the specific implementation details and system security boundaries.
Mitigation strategies for CVE-2018-12109 should focus on immediate software updates and patches provided by the FLIF development community, as the vulnerability represents a known flaw that has been documented and addressed through software version improvements. System administrators should implement strict input validation measures for image files, particularly when processing user-supplied content, and consider deploying sandboxing techniques to isolate image processing operations from critical system resources. The vulnerability demonstrates the importance of proper memory management and input validation practices in image processing libraries, aligning with ATT&CK technique T1068 which covers local privilege escalation and T1203 which covers exploitation for privilege escalation through memory corruption. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such vulnerabilities, while monitoring for suspicious image file processing activities that might indicate exploitation attempts. Additionally, regular security assessments of image processing libraries and components should be conducted to identify similar vulnerabilities that might exist in other multimedia processing software.